(Been visiting Alaska for work and play since 1979, lived here since 1998)
Bears are only scary because they’re new to you, not because they are any objectively relevant risk. I felt the same way my first time in Africa. Crocs and hippos in the river! Lions! Elephants that pop out of seemingly nowhere as you’re eating an orange! There are over 2 million tourists in Alaska each year and we almost never lose one to bears. So far under 1 in a million risk. Sure, you’re out in the wild more than most tourists, but you’re going to be smart about it, right? More on that later. Every brown and black bear I’ve encountered while hiking did the right thing and headed the other way (less three black bears we shot and ate). I make noise when the sight lines are poor, the water noise masking my approach and there’s fish or berries around. If a companion wants me to, I’ll carry pepper spray. I’ll only carry a gun if 1) we’re trying to eat the bear or 2) it’s work rules on a job site (our company trucks have 12-gauge shotguns loaded with flash-bang, bean bag, slug, slug, slug, slug.
If you’re still concerned about bears, the best guidance is from Stephen Herrero’s books – an actual PhD researcher who looks at all the data from throughout North America. Short answer: Pepper spray has far better outcomes for humans compared to guns (and vastly better for the bears).  Slightly longer answer: group size is the bigger variable for if you’ll have a bear encounter (or even see one). A large group of people NEVER travels quietly, so they spook the bears long before they get there. If you’re nervous on a trail, tag along 50 feet behind a talkative group and, alas, you’ll won’t see any bears.
Of all of those hikes, the ones where you’re most likely to encounter bears at the ones in Denali NP. Thankfully, the NPS has them trained well – or rather, has avoided them getting habituated to humans and associating people with food. They have strict rules for backcountry hikers and especially backpackers that have kept the bears wild.
I’ve never found parking at Denali NP to be an issue (unlike Yosemite). Follow the signs for the shuttle buses. Make reservation(s) in advance. Don’t want till the very end of the day to catch a bus coming back, since other hikers do that and there are only so many empty seats on the returning buses. Don’t use the bus only to get 15-20 miles in for a day hike. Dedicate a day to take the round trip out to Eielson Visitors Center (dang, or is the road closed due to a landslide this season?) to see a lot more critters. Between the bus driver and all the other eyes on the bus, you’ll see far more bears, caribou, Dall Sheep, etc than if you’d been on your own.
Dress in layer and wear things that dry out as you wear them. I prefer to let myself get moist in the drizzling rain dressed in poly and nylon to stay warm, rather than attempt to be waterproof and be in a self-created sauna all day long. I never step off an established trail in Alaska without long-sleeve shirt and long pants of 100% nylon. They can be thin (I like a 100% nylon fishing shirt with a collar), but you want the tough nylon to take the brunt of the willows, parsnip, wild roses, and Devli’s Club. I wear low-cut, ventilated hiking shoes with very good socks and accept that my feet will be wet all day. Bring dry socks and camp shoes if you want.
Are you renting a car? It’s the easiest way to get around (and you’re going to a LOT of different places), but they’re not cheap in the summer. Historically, rentals cars out of ANC or FAI were $29/day in winter and $500/week in summer, but then there was the pandemic and then pent-up demand. Looks to be around $1000/week this July (down from $2000/week two years ago). I’ll often conspire to leave a car at ANC for friends. Compare on Turo – elsewhere I find Turo to be about 50% of rental agencies and an older local car is probably safer from mischief at a trailhead than an obvious tourist’s rental car. For the rental car agencies, anywhere in the US, I compare on carrentals.com Hitchhiking is more viable in Alaksa than elsewhere in the US and single females get rides faster than anyone else. Still, you’ve got a lot of stops planned on a short trip, so your own car would be really helpful.
The Magic Bus 142 isn’t out the Stampede Trail anymore. Here it (and I) are at UAF:
although the replica they used in the movie is front of a restaurant in Healy, north of Denali NP.
I like The Museum of the North on the UAF campus for half a day. It will eventually display the original Magic Bus, but it’s being restored now in the Engineering Building.
Nat’l Geo maps are pretty and great for day dreaming about the trip in advance. I’m increasingly using my phone and an app (AllTrails, etc). There will be basic maps for free at Denali NP and lots of options to purchase maps once you get there or at Walmart, REI or any bookstore in any town.
Sounds like you’ve got budget for some adventure stuff. White water rafting the Nenana River just outside Denali NP has totally changed since they went to dry suits. Now it’s an exciting ride and quite safe. 35 years ago when I first did it, they just gave you yellow rain slickers and if you went overboard you’d be in a very bad way, so they stayed out of the haystacks and bumpy stuff. There are also four-wheeler rides and zip-lining available out of Healy.
Everyone has bear spray for sale in Anchorage and Fairbanks – Walmart, REI, Sportsman’s Warehouse, and I think Safeway. All those places also have backpacking stove fuel. I just got back from Fairbanks; if I have another trip north of ANC before July, I could stash some bear spray at, say, the base of the MilePost 39 sign in a ziplock bag. It saves folks having to buy it for $50 and then leave it behind. Or if you go to the Kenai Peninsula early, pick it up from me in Kenai. Propane stove and fuel, too, if you’re basically car camping. If you have lodging in Anchorage, I’ve dropped off bear spray at hotels and AirBnB for future guest arrivals. Some lodging might have bear spray for loan (the previous guests couldn’t take it with them). Call ahead and ask. It’s more weight for the remotely unlikely benefit for me on the hikes you describe, but to each their own. HYOH. BYOBS (bring your own bear spray).
I’ve done that trip to Grewingk Glacier, but privately. We reserved a yurt on the salt water a mile from the beach trailhead to Grewingk and hiked in. We didn’t kayak on the lake (although I’ve got a pack raft if you could borrow want to do it on your own) and that sounds like a cool experience and, yeah, photo op. We got out there on a water taxi (all the locals use Mako’s Water Taxi) to get to the yurt (or trailhead) and get picked up later. Leave your schedule a bit flexible and head out when they’ve a got boat going there anyway and pay a seat rate rather than rent the whole boat. Or do the packaged tour if the price is right for you. Other cool things to do out of Homer: Make reservations to the Saltry restaurant in Halibut Cove in part because it includes a 45-minute trip on the Danny J from the Homer small boat harbor – an old wooden boat, each way and you’ll see birds, otters, and sometimes whales on the way to lunch or dinner. Halibut Cove has boardwalks to wander before/after your meal, and an art gallery or two. The Pratt Museum and the Islands and Oceans Visitors Center are each worth a visit, especially on a rainy day. When you see the views from Homer, you’ll see why they got all the artists. Here in Kenai, we only get these views in one direction:
while Homer has glaciers and volcanos on three sides.
In addition to world-class sea kayaking out of Homer (I’ve got a bunch on the garage ceiling), there’s the OTHER wilderness canoe trails area in the US. The one that’s not Boundary Waters. The Kenai Canoe Trails can be a day trip, a weekend or two weeks. You can paddle around the first few lakes, go further out to the most distant ones, or make it through trip and get flushed down the Swanson River 
The “Difficult passage” isn’t difficult, it’s just tedious. You’ll leave a lot of green rocks behind (if you borrow my green canoe).