I have the Foretrex 101 (as well as the Garmin Geko 201).
I am still learning about the Foretrex 101, and am far from an expert on its features. However, I will try to help you answer your specific questions.
You ask whether the 101 will display the bearing for you to travel from your current location (determined, for example, by marking that spot as a waypoint in the 101 while you are standing there) to another location on your map (a location that you have stored as a waypoint in the 101, either in advance or from a UTM that you identify as your desired destination on your map as you stand in your current location). It appears the answer to that question is at page 55 of the manual for the Foretrex 101, in the Appendix, where information ("data field options") that can be displayed on the Navigation Page and/or Computer Page of the 101 is described as follows:
"available data field options for the Navigation Page and Trip Computer Page" include "Bearing – The direction from your current location to a destination."
From the above, it seems clear that the Foretrex 101 will display the bearing to use for traveling from one location on your map (for example, your current location with its waypoint entered into the 101 as you stand there) to another location on your map (with its waypoint entered into the 101 in advance of your trip, or even as you stand at your current location). You can then set your compass with the bearing provided by the 101 and be on your way, but with two caveats:
First, make sure that the settings for the 101 and your compass are "on the same page" as far as any declination adjustment for True North and Magnetic North that may be required by your map. The 101's manual, at page 50 in the Appendix, discusses these adjustments and settings, as well as noting minimal effect of "Grid North" as a factor.
Second, make sure the settings for "angle unit" in the 101 are set to "degrees" rather than "mils" so that bearings data will be displayed by the 101 in the format that you will no doubt want for transferring the bearing data to your compass. The setting for the "angle unit" is also described at page 50 of the manual.
Your first question is also answered by the above effort: Yes, you can very easily determine your current location with the Foretrex 101, so long as your batteries aren't dead and a large portion of the sky can be accessed.
Note: Another poster mentioned that the 101 displays a compass direction when you are moving, but not when you are standing still since the 101's compass function is not magnetic (differing from the 201, which has a magnetic compass). I believe the compass reading displayed by the 101 when you are moving is actually your "heading" (your moving direction), which is not as precise as a "bearing" that can also be displayed by the 101 re your destination.
For me, the 101 is an amazing item, definitely worth it's weight of 2.61 oz w/2xAAA Lithiums and w/o wrist strap. I made my decision based on the BPL review cited by the other poster to this thread, as well other reviews and resources elsewhere.
I purchased my 101 through Amazon for only $84.99, per this link: http://www.amazon.com/Garmin-Foretrex-Wrist-mounted-GPS-Navigator/dp/B000255I8W. A data cable to upload/download data between the 101 and a computer is also worthwhile if you use mapping software, but a data cable is extra expense since it doesn't come with the 101.
JRS