You seem to have missed things that are written all over the site in the help files, the Academy, the forum, and the terms. They are clearly spelled out and perfectly legal.
7 to 14 day clearance is written in multiple places but here it is from the official Terms of Service:
Revenues are only made available for withdrawal from the Revenue page following a safety clearance period of 14 days after the order is marked as complete. Top Rated Sellers and Pro Sellers are eligible to withdraw revenue following a safety clearance period of 7 days after the order is marked as complete.
You are welcome to make your own freelancing site if you don’t prefer this one.
As for the commission, that’s also stated in multiple places. Here it is from the help page:
When your order is successfully delivered and completed, you will receive 80% of the total order value. For example, if you price your service at $10, you will receive $8 for a completed order. For more information, see our Terms of Service.
Perhaps you should do more reading if you plan to stick around. Places to start:
The Fiverr Academy (Best for brand new or struggling sellers)
The Support Team Knowledge Base (use search for best results)
The Tips for Sellers forum category (A good place to read tips and post tips for others - for a place to ask questions keep reading)
The Fiverr FAQ (Great to read simple Q & A or post a question IF it hasn’t been posted before)
The Conversations forum category (Good for general chit chat or questions that might lead to a full discussion)
It’s also good to become familiar with:
Summary on Fiverr Communications