I like to be able to help new sellers if I can, but here I hardly know what to say -- you are complaining about a policy you should have been aware of before you began selling (assuming you did your 'homework' beforehand), a policy that is in any case a temporary situation until you become established.
There are very good reasons for this policy. Think of it as being similar to a probationary period at a new job. Once you've proven your merit, you aren't supervised as closely as at the beginning. This is sensible, and it isn't as if eBay or Paypal make it a secret from new sellers.
New sellers need to develop careful selling habits and build up a reputation of being dependable and professional. This particular policy restricts "fly-by-night" sellers - in other words it protects buyers from sellers who haven't yet got a stake in maintaining their eBay reputation. I'm not saying you are this type of seller, but everyone has to pass eBay 101. Everybody goes through it if they start from "0".
Judging from the fact that you've already received one negative in only 8 transactions since late January this year, you should be concerned less about the funds being held back and more about your seller profile. Now that your FB score is less than 90%, in buyers' eyes your credibility as a seller may be in jeopardy.
Believe me, there are many other restrictions and rules you'll encounter as a seller, most of which you have to accept if you want to continue selling effectively on this venue. Whether you've sold elsewhere or not, as a new eBay seller, you may find the policies different (and more strict than some other sites), and you need to review them carefully. Otherwise success here will be limited.
My best advice to you if you are really serious about long-term selling on eBay is not to start out with issues and petitions before you are even invested in eBay selling, but to get fully familiar with the seller policies, try to follow them closely for the next 6 months to 1 year, and firmly establish your seller reputation.
As an example, that negative you received could have been avoided by being very careful at the beginning of your eBay selling career to not list any item that might need to be pulled as non-available, or might have a chance of being sold elsewhere. You may be able to absorb this kind of FB without too much damage when you have several hundred transactions, but not at the very beginning.
I am not trying to be harsh, but from a seller's point of view eBay is a more demanding site than some. You must accept certain restrictions. It requires a serious, professional, very customer-friendly attitude to be successful as a seller, and you have not started out with the most effective approach.
Put aside complaints and petitions about policies for the time being. Once you have a few hundred FB points under your belt, you will know what is worthwhile trying to change on eBay and what is not. Focus your time and energy as a new seller on being the best seller you can according to eBay's rules, and you can do well here.
Whether this is a duplicate thread or not, it is probably worth repeating...
