This is a tough one. I've been off and on more than a decade now and usually in that field, including managing. Currently freelance escorting, but that's for my own reasons.
To answer some of your questions ...
Yes, many clubs will require you to rent an ad board at their location for a very nominal fee. This fee is usually less than a single decent tip, so you're never out any money. It's still a weird practice to me though, shouldn't the club be buying/featuring me an ad board to advertise that I am working there?
Often times there are applications and interviews to go through. They want to see how you behave, emote, your personality, what your avatar looks like (clothed and naked), etc. Some of them have been harder than some of my RL interviews, which again seems unnecessary. Check me out, see how I do, if I don't work out, fire me. To require formal interviews and two hours of chatting is silly; it's easy to tell if a girl is any good in 30 minutes on stage just watching her emote and behave.
And yes, application fees are not unknown. I've paid them, and also refused to pay them. In the end, they feel scammy. Here's my 11 years of dancing/escorting experience, hire me or not. Like ad boards, just another way for the club owner to make cash to run their place.
Required hours. Most good clubs will require some commitment. Usually like 4-6 hours per week. And for the love of anything, don't go AFK when you are performing. But don't kid yourself, those 4-6 hours will feel like work when the customers are thin in the chairs.
Tips. Most good clubs will take some small percentage of your tips. If it's more than 20%, the club can go rot, imho.
Freelance clubs. There are a number of large, popular, well-known freelance places where anyone can dance/entertain. The issue with these is that there are often 20-30 girls dancing, and a single guy or two as customers. I have never seen any place with as many customers as girls in these places, not even close. Even at the biggest two of these. If anyone tells you different, they're BSing you. Furthermore, most clubs and freelance places have rules about no IMing guys directly, to save the place becoming a feeding frenzy of desperate girls slamming a poor guy with 20 IMs all at once. You can only say hi in local chat until someone approaches you and IMs first. This does mean everyone has a fair shot, but also you're just one of 20+ semi-naked girls hoping for a nibble.
Owners. As someone who has danced through managed, I've seen them all. Misogyny is rampant, sadly, among the male club owners. the assumption that you'll "put out" for the male staff is a common, sad theme, even in some of the better known places. I'm there to entertain customers and have fun, not fend off persistent advances from some horny club owner. Run from those places. They are pits of drama and an environment of girl-vs-girl for popularity. And while many of the female owners are chill, I've also been in places where the women owners can often be far more toxic and mean than the men can be. It's a hard business to run, and girls and clubs are a dime-a-dozen.
You talk about clubs not being dead. Hmmm. I have news for you, even the popular ones? You can be on stage 90 minutes with another few girls and not see a single guy. Often. The other thing is a guy will pop in, say nothing, then leave 30 seconds later. this goes for big popular clubs and small ones. Fancy, well-run places, and dives. There are so many to choose from and this isn't 5-10 years ago when stripping was at it's peak. And while there are regular guys at every club, it gets expensive to visit frequently and have to tip all the time, without even the cost of escorting added in if the guy wants to take a girl home.
The other girls. One thing that weirds me out in this line of work is the diverse range of avatars in any one club. I'm not talking ethnicity here, and I am certainly not curve shaming, but I've been in (good) clubs where the girls range from nearly pre-teen look through to tatted up nearly 7' tall biker chicks with HH cup breasts, little fairy wings, and a butt the size of a wide lazy boy chair. It takes all kinds, but you can not count on consistency of looks and if that's important to you, check the place and staff out before signing on.
Ask the club owner about turnover of staff, traffic stats, how much the average girl earns in tips (and keep a spreadsheet of your hours, tips etc so you know if you're earning what you want), how long they have been in business, customer numbers and how much they spend on average, etc. If the owner won't share those with you, they are hiding something. And don't let the "that's a business thing" line of BS stand ... it's SL. Remember, if they are putting you through an interview, interview them right back. You get to ask hard pointed questions too, you know. Give me the info I need to commit and make a decision, or go away. Honestly, it's not anything you have to hide, unless you're not what you say you are. I've seen that one countless times.
If you want to reach out to me in game I'll give you some recommendations of decent clubs, but many of them will have some degree of the above requirements.
Hope this has helped somewhat.
The second picture, btw.
ps. Come and stop by my small freelance club sometime and chat. I'll tell you anything you want to know about this crazy business.