Selling on eBay with PayPal - blocked account balance?

Question

PayPal

Placed a lot → sold the goods → received money [but they are blocked for 21 days].
Quote:
Depending on your eBay sales history, we may temporarily place a portion of the funds received from each of your eBay transactions into a blocked account balance. These funds may be held for up to 21 days from the date we told you that you could ship the item in question. Other restrictions may also apply.
The only problem is that I didn't read the rules and didn't know what would happen. He planned to produce goods with the money of buyers and sell them. There is no capital.
I have now sold two items. ($800 each)
There are many different questions.
1. How to quickly remove this blocked balance?
2. It is known (on the forums) that if I add a track to a sold product or the buyer gives a positive review, then the amount is unlocked. Is it so? Is it the whole amount? Are there any other conditions? (This option seems to suit me, because you can come up with something with loans, even with interest-free up to 1 month, withdraw a loan → produce → sell → withdraw from PayPal → repay a loan)
3. What should I say to buyers?
3.1. Write directly in the lot on eBay what is there and that I can send the goods only after 21 days?
3.2. Do not write, but send after 21 days by telling this in a personal?
3.3. Loan option?
3.4. To score on everything, because too difficult?