one thing i wasn't happy with from the original announcement onward was the communication. they did a pretty good job hooking people in, but frequently their communications suggested they would be much more transparent then they actually were. there were a lot of promises of compatibility, balance fixes, confusing rule adjustments, etc, that were given in vague terms that suggested much more than we actually got.
...well, they decided to replace races, how you get build up stats, and subclass levels.
mostly you can slot in 5e options directly, but differing subclass levels and feature interaction make porting subclasses feel very iffy if you don't have a strong grasp on editing mechanical rules safely. mostly, there isn't a simple nice set of instructions you can follow for using 5e options with a ToV based. you have to do a bit of leg work.
maybe this is a hot take, but i think having broad weapon proficiency makes sense for fighters and maybe monks.
pretty much every one else that gets weapon proficiencies should be choosing one or two weapons that they've trained with, and they should need to re-train over a week or more before being proficient with something else.