I will take some pictures of it for you. Unfortunately i can't do it until weekend, not at my bows place currently. Let me still try to answer some of your questions.
The ILF limbs i tried (W&W, Mybo) fitted perfectly in there. I will take a picture next weekend, maybe i can talk someone into borrowing me limbs for additional photos.
I bought the riser as a blind buy. At the time i was looking for a new riser i had my eyes on different brands which i could actually try out: I really like the Fivics Patina and the Hoyt GPX was also in my list. I would put the Mybo Elite in the same category with these. No shop around me carries the bows by Mybo so far. I already own a stabilizer set and some minor parts from Mybo and was always more than happy with quality, finish and the product you get for the money. Knowing that Mybo is the house-brand from Merlinarchery UK helped on the decision as well. Considering the price of the other risers on my list and the Mybo... Yeah, it was a lucky shot, but i am super happy that i tried it. And i feel no remorse, because all the effort Mybo/Merlin put into that bow is worth the money for it.
Screws: The screws are not overly small, not sure about the actual size, though. It felt as if they are comparable to the standard used in other brands. I don't think it will eat the threads during normal use.
Grip: The standard grip on the Elite is kind of a black rubber, somewhere between low and medium wrist and rather slim. Other than typical plastic grips it has a silky smooth touch to it and really bonds to the hand. For me as a mainly compound shooting person it felt great because it was so slim, but as mentioned before i switched it for a higher-wrist grip which i built myself, but Mybo/Merlin offers also wooden grips to buy.
Balance: Phew, without stabilizers the bow sits pretty straight in the hand, maybe a bit heavy on the top side, but i would need to verify that first before claiming it. In any case it feels very stable, actually better than the Fivics, but that might be subjective. It definitely balances better than the GPX.
Vibrations: I only shot it with my preliminary stabilizer setup and the bow was feeling good. Not dead in the hand style, and not super quiet, but it 'feels' stiff, even though it is something you really cannot feel. Maybe because there are no parts that are super slim and prone to bending during the shot, maybe due to the well-constructed limb pocket, i don't know. I can just describe it as feeling stiff, something i would attribute to be rather positive. But here i need more and fresh comparisons to other bows before i can make more of my super subjective statements.
Hope it helps, pictures will follow later...