-What would be the minimum commitment?
-- Ten years from UPT graduation.
-About how long to upgrade?
-- About 2 years +/- 6 months.
-If I do fly for a regional and reserves part time, when would I fly and what sort of things would I do on those flights?
Depends on the airframe. Most units have a weekly flying schedule, to include certain night flight schedules. This is for local training and does not include TDYs, mobilizations and any other kind of overseas type of excercises some folks at the unit may be involved with/volunteer for. I can't speak for all airframes but as far as the co-pilot side, you know, standard (gear, blame for anybody's bad landing/airmanship, paperwork qweep, and radios). All that aside, we get less stick time than co-pilots at the airlines (where it's mostly every other leg), at least from my experience at the schoolhouse. Of course that's more AC dependent than anything. The ACs and IPs of course get beaucoup stick time. Overall it's more relaxed on the Reserves side than on AD though, so you might still get more stick time as a co on a Guard/Reserve unit than if you were AD. The reserve QOL after chocks in is, of course, diametrically better.
-Do the reserves get called up for deployment?
Yep. Ops tempo depends on unit, airframe, taskings and the alignment of the moon. It all depends. If you're asking about non-voluntary mobilization, not happening much that I know of. Everything so far has been on a voluntary basis; so it's not the flying club of the 90s but it's not the Army "Reserve" either. Unless another 9/11 happens I dont foresee any non-vol tasking popping up. Things will continue to cool down with the next administration, but so will the availability of jobs.
-Say I do a 4 day trip(civilian) then have 3 days off, am I at the base those 3 days flying?
Not necessarily. You can request (more like tell them) mil leave to attend to your military commitments. Most units want you there on UTA or "drill weekend", so if you had a trip then you would request mil leave to attend, essentially dropping that trip at the airline. Or you may choose to complete your training during your days off at the airline, where your description of "3 days flying at the base' would be more acurate. Good luck with that though, from a QOL perspective. Ballpark, most people who do the regionals drop trips because it pays more per day to work at the unit than at the regional, and still want some semblance of a life. Most major carrier types do the opposite, they lose money when they mil drop to work at the unit, so you might see those types do their events on days off. Then again they may still want QOL and mil drop trips at the airline at a loss but to retain days off. Everybody has a priority when it comes to those iterations. Also most units have a plan for the upcoming month somewhat in advance so people can plan ahead, particularly with the airline dudes.
-What's the pay like?
Once again, depends. The absolute minimum guarantee for a pilot in the guard/reserve is 48 drill periods, 48 Training periods, 14 days of annual training. That's about 13K for a 1LT married. Everybody does more than the min though, so depending on how much extra sh$t you do then the pay goes up from there. How many man days you get, TDY you volunteer for, if you get put on orders, etc etc is up to you and the unit, and of course the pecking order at said unit as well. As a 1LT if you make about 40-45K you had a great year..that's about 4 man days a week plus the guaranteed periods, which you won't get [4 man days/wk] if there's more than one of ya fighting for the same pot, but can be attainable. If you can find a set of orders (like for a year) you're set then, as it is AD pay without the AD qweep. There are also the full-time jobs at the unit; hard to come by, unlikely for a new guy to be considered for them, but are federal GS scale jobs along with all the trimmings of govt cheddar jobs. You can make 6 figures in less than 10 years of working that position and be home every night. You'll have to fight me too for one of those though (yummm cheddar..). That's the jist of it.
-How long will it take to actually start flying the plane I'm assigned in the reserves?
Initial qual in the aircraft will be about 0 months through 1 year after UPT graduation depending on many factors. UPT dates could be zero months to a year+ from commissioning date, and commissioning date could be 1.5 months through 2 years+ from hire date. So plan accordingly.