Tremolo Snare Drum playback is bad

See the attached project. There are multiple issues with the snare drum tremolo:

1. the first line (8 bars), does not have any dynamics markings. It seems like the snare drum samples are mostly played at "mp", but the tremolo is played at "f".

2. The tremolo is always played in a way that seems to match a crescendo, and it finishes at its peak (though sometimes starting with a strong attack, sort of like a sfz). This is generally masked by the fact that there's typically a snare hit at the end of a tremolo, but on the penultimate measure of every line I have a rest following the tremolo, and the transition is quite jarring

3. As far as I can tell, there are two round robin'ed samples for every dynamic. Some of them sound quite different from other. The "f" dynamics, for example, it's clear that one of them has a much, much stronger first attack than the other

These are all 64th tremolos, but 32nd tremolos have similar problems (16th tremolos don't seem to have quite the same problems).