1-These numbers aren't publicly available, but I'd imagine our top players are getting upwards of low 6-figures (there are some rumors of a guy or two getting $200k, but AFAIK they're just rumors), and it goes down from there. I am guessing that the vast majority of players on the team are probably not making more than $10k-$15k at the most, but as I said, I am just guessing. Marcus made a post on here a couple weeks ago saying they were about $500k-$1M short of overall NIL goals, and about $100k short of their goal for the transfer portal, specifically.
2-Also according to Marcus, if we made up that $500k-$1M shortfall, it would put us in the top 4 of FCS and competing favorably with Mountain West schools.
3-I imagine this is worked out with the NIL in conjunction with the businesses/people paying. Remember, that in order for the player to receive the money, they have to provide something for the person/business/collective paying. That can be (as the name suggests) their name, image, or likeness to be used for promotion, events, advertisements, etc. Players are not allowed to receive money for simply playing.
4-I covered this a little in #2, but yes, the top of FCS is on par with many (but definitely not all) G5 FBS teams.
If you're wondering, I do not know if MSU is in the top 4 of NIL for FCS, but I imagine NDSU and SDSU definitely are.