Hi, OP.
I have been trading for nearly 2 decades now.
Use my local site to trade in the volumes you describe, but in AUD, and yes you do buy/sell BTC in the process of trading. So im not sure if it will suit you.
https://btcmarkets.net/ You do have to provide your full ID,however I'd trust them with up to 100kUSD no problem. My last trade took 5minutes (send coins from wallet to exchange+sell then withdraw fiat),and the 15k fiat withdrawal was in my bank account within 48hrs.
I was lucky to earn my btc when i tried mining years ago,however my advice is to buy 10btc, secure them in a wallet for 3+ yrs then consider trading them long. In the meantime you take advantage of any spikes/dips and transfer to the exchange to trade...>> then move it back to your secure wallet(s). My re-positioning value is on $500 dips while the long term trend is up, a trend which does not look like changing for years.
cheers
groko