The negative opinion for a declining a 3-some is very minimal and goes away pretty fast. Is there to prevent spamming the same request after they've been denied. It starts as a -1 but goes down to 0 in 2 weeks. So I wouldn't worry about it.
Also someone needs to have a positive threesome opinion to even ask you about it, so I don't think you should get many of those.
As for the meetings not having anyone in them, that's odd. The system is supposed to create new members if there aren't at least 3 before the first meeting. The old leader has been kicked out so she wouldn't be there however. But there should be at least 3. I can't think of any reason why you wouldn't see anyone. So give me more details of exactly what you see. You get the meeting announcement and you go there, what happens next? Do you get the option to use the drugs or not? Do you then get to ask a volunteer or pick someone? Can you get that far?
As for the character using the default image... what's the ethnicity? There aren't may 50+ year old character images so those can run out if for some reason your game generates a few of them. For instance, there's 2 female asian 50+ year old images, so if a 3rd is needed, it's going to put the default image. Anyway, it's not going to use a 30 year old image or a black woman's image.
As for the meetings, I go there when it tells me the meeting is happening. Nothing at all happens. I am in what looks like a lecture/training room, it is empty, nothing under People Here and no dialogue/menu options, just the usual action menu options that I would have elsewhere.
I do have another issue with the current game, not something that bothers me, just something you may want to be aware can occur. My elections aren't taking place. I've been in the same primary for nine months, which was the first primary of this playthrough. Like I said, I'm not bothered, I have four commissioners that I generally work with and don't have any need to change anything.
As far as the 55 year old with a default image is concerned, she is white, but equally I haven't kept that many image sets for more mature women. I do remember having one game not long after I first started playing where the majority of characters generated at the beginning of the game were using default images, but that hasn't happened again since.
I noticed that the threesomes weren't generating any negatvity anymore, in fact it's the opposite. I can say no to a proposal or back out of one that I've agreed to and, in both cases, it says both women like me more. I haven't checked their stats to confirm that that's the case, but that's what it says in the text window.
Another thing you may want to be aware of is that I am still getting the cops called on me when in my club, by my own staff no less. She was probably just jealous, because it wasn't her that I was fucking. That brings up another question though. Is there any benefit to making characters like voyeurism, if I plan to shag about inside my club?