1. There is no regulations stating it is illegal.
2. You can find servers where you do not have to pay for just playing there. Yes, there are " dominando" guilds over there too, but, they might operate in a different way. For example- they have priority on taking the spawn (they can claim it at any time) etc etc
2. Is it really Player abuse? Very subjective considering: It is within Guild internal regulations to ask money/services from new incomers or their present guild members. It might be just guild money- for example for those who lost lots of money during the war for the guild, or for char transfer for the words which they are planning to have war etc; etc.
From what I noticed- a proper Dominando guild are organised properly and have strict restrictions to their members activity- You must be on Team Speak; You have to have characters above certain level on other servers; you need to have access to certain places. Also- you have to be there when needed - when there is an attack- you leave all behind and go there. By being active, you receive benefits such as "hunt claims" and some other. They are also punishments if you are not turning up on actions, and members are "kicked" from the guild if they are not behaving accordingly to the guild conduct. I believe it is completely fair and straight forward- as also great for leaders to keep all in control and in check.
3.. It is your personal opinion that leaders have lots of $$. Even if they do- this is in my opinion reasonable. Have you consider how much time they are spending on calculating lost/ profit of cash& exp from the wars? Have you consider how much time they spend into helping new- members to organise access/ quests etc? How much time they will sacrifice to observe enemy moves? How to resolve conflicts within guild (which will be plenty) as also outside guild?
I will not mention that they will be always commented on every single "mistake" and laughed at. Most of the people are getting triggered and are not capable to handle even little bit of criticism.
Everyone will have different experience with guilds. Of course there will be also some "lovely" players who will want to earn money by being in Dominando guild. Inevitable.
Ask yourself question: Are you capable of sponsoring and being in charge/responsible, keep the morale of over than 500 guild members- which almost every second of them thinks he knows better than you?