I have two friends who are going to take it. I have between 15-16g of powdery Mimosa getting ready to be taken with moclobemide. That is about how much I took when I first tried it, which was a very pleasant trip. In fact, there was an early stage where all my anxieties and worries completely disappeared but where I was still very freshly in the normal world. They have quite a bit experience with psychedelics but I don't want to take them too far. Is 7-8g decent for a beginner?

MHRB is ~1% DMT. That's a 70-80mg oral dose. Sorta on the high side for a beginner. Maybe break it into two doses, separated by an hour or two?

what is the source of harmalas and how much are they taking of that? 15g is way way to high for most people. Even 8g is too high for many. I would make sure they get a sufficient dose of the harmalas and then take the mimosa 15 minutes after..but slowly work the mimosa amount up from about 3 or 4g. You don't want to freak them out and scare them off for good the first time just because they overshot it a bit

and its good to keep in mind that many people repeatedly get mimosa with closer to 2% dmt content

I took about 8g my first and only time. I thought I became "enlightened" since that was and still is a big thing of mine. I was looking at books around me and laughing that I thought people actually existed that wrote them. It was very very pleasurable but I think I was ready for it because my interest and long commitment to buddhism/waking up. These people's minds are not nearly as into that stuff.

I ended up spilling a little bit so I'd put it at 7g each probably, not to mention what's been lost in filtering. Since I am using moclobemide as the "harmala," should I have them take that and then start drinking (sipping) the drink after that? I definitely want to give them a very pleasurable first-time experience.

Yes take the moclobemide a half hour before, otherwise you won't have effective MAOI in place when the Mimosa soup goes down the hatch.