Concerning fund transfers from balance to other bank acco

Hello Flutter, i found out that a minimum of 1000USD is needed for transfers to bank account. Few questions

I set up my dollar account to store funds in balance instead of instant bank settlements. I run a system whereby users will need their funds immediately after a sale irrespective of their balance. If paradventure a dollar payment is made, and i have a balance that is less than 1000USD, will i be able to send funds to the users account. Users will have bank accounts round the world, and will be requesting their funds as soon as they make a sale.

My systems priamary currency is in USD, and i will also love to settle Nigerian sellers, at what rate will they be settled,black market rate or normal rate. eg, 1 dollar at normal rates could be 367 while the black market rate is 475, with this sample, at what rate will customers be charged, at what rate will sellers be paid, will Nigerian sellers need a domicilliary acct to receive their funds, since all funds received by the system is stored in USD.

Flutterwave claims that its users will be able to send funs to bank accts around the world. Are there any countries excluded. My system will be receiving payments from different sellers around the world and will be having vendors around the world too. Will i be able to actually send funds to people in any part of the world,if true,what are the fees involved.

To send funds from my wallet (in USD) to a nigerian acct, will i need a minimum balance of 1000USD to send payments to them,will they also need a domiciliary acct or shouls their normal acct will be enough??

Thank you