Hi, I didn't buy the course (yet..)
For 2) I would fold EP bottom low rundowns hands like 7654ds, even JT87ds and low DP like 5544ds because they lake nutiness and play poorly MW and OOP, even if it is a GTO open.
In 9-handed : be even tighter in EPs and nutiness matters a lot...

I have bought the course and am planning on doing a review at some point here soon. He recommends opening 12-16% utg, which I think anything higher than 13 is going to be too loose at 98% of all tables you will encounter below about 2/5 online and 5/10 live.

When I take on a new student who is not yet beating the games for a good clip, there are two things that I pretty much do always. The first is to get them used to the fact that winning small stakes plo is pretty boring and that they're going to be called a "nit" a ton. The second thing I do is to get them to know a proper 12% rfi range like its the back of their hand. In many disciplines there are a lot of "hacks" or 80/20 type pieces of knowledge that if applied, can get someone proficient very quickly. In ss plo, a proper 12% rfi range is one of them as it is a range that is used SO often. A profitable 12% RFI range is designed such that it will thrive in multiway pots. Thus, you really don't need to make adjustments from 6 max to ring unless you're playing at an extremely crazy table where all pots are 5-6 ways and usually 3 bet. In that case, you can go ahead and cut down to 9-10% from these positions, but 12% would still be profitable (it would just be higher variance.)

The GTO EP opening range contains some hands that are used for low board coverage (like I think 7766ds, 8764ds..) . These hands are pretty bad MW and should not be opened EP on loose tables.

Thanks for the review forehand, I'm really waiting for it.