Hi Matt; the mandolin isn't really designed for finger picking; double strings and narrow string spacing tends to make it difficult, although I've seen it done with very pointed, banjo-style fingerpicks. Flatpicks are much easier to use, and to my mind fit with how the instrument was built to be played.

The barre chord thing is an adaptation issue I think; most acoustic (non-classical) guitars have a radiused fretboard, whereas most mandolin fretboards are flat. For a guitar player this means the middle strings aren't quite where you expect them to be under your fingers. This is compounded by the relatively high string tension on a mandolin when compared to either a guitar or a banjo, so you have to press down a bit harder to get a clean sound. A refret with taller/fatter frets sometimes helps, and you can get mandolins with radiused fretboards.

It's sometimes easier to play chord inversions that have partial barres (just two strings), or try to get used to the Bill Monroe 'chop' style chords that use all four fingers (as a rule)to play 'closed' chords anywhere on the neck. Some big stretches involved in those though!
Hope this helps.
Tim