How do you sell?

I’ve only ever bought and sold small numbers and heard scary stories of people who had their fiat locked up at kraken, Coinbase and other exchanges for a variety of reasons after making big sells.

But if you had like 5-10 coins and wanted to sell that right now, do you go about it the same way as if you sold 0.15? Transfer it from wallet to exchange m, sell it for fiat and the withdrawal to you private bank account?

Wont a transaction of several $100k set off a bunch of money laundering alarms and taxation rules you’ll die trying to admin your way out of?