Federal law requires that they release you in time to travel to your duty location and then get adequate rest before reporting. You are also get the same on the back end of your duty.

How various airlines implement this varies. They CANNOT require you to do your reserve time on your scheduled days off, although a few rogue chief pilots have tried this in the past.

My company prefers that I notify them prior to the bid, in which case the mil leave is pre-assigned and my schedule is built around it. I block off the time I need including travel days. They actually give me "virtual credit" for reserve days in PBS so the system does not build me a full line during the rest of the month, which might otherwise take my days off way down.

Also, you can drop short-notice mil leave which just overwrites your existing schedule. Airlines don't have to like this, they just have to do it. Worst case they complain to your CO who will probably just blow them off. Your CO has no incentive to bust your balls to make an airline happy.

After ten years of war, the feds have pretty much sorted out any large company which tries to play games with their reservists. You won't have any issues.

Military flight and duty time do NOT count against FAR limits in any way. You just want to be adequately rested before returning to 121 flying.