Yes. Currently there is a 2mil USD upper limit on all trade. If your trade is bigger than that, it will get reverted.
Also, we recommend you to put Slippage Tolerance at the default setting, which is 2%.
No. We designed Integral to have lower trading costs than any other exchange (including Binance, Uniswap, etc.). With future L2 deployment, trade of any size will be able to enjoy this cost-saving perks.
No. What we mean by block trading is that Integral enables users to trade in a big amount with cost less than Binance, but still being on-chain. Right now it's really expensive do such trading on Uniswap.