Which method yields the highest profit?
Is not the BCT/ Fiat trading or BTC/Altcoin trading. It depends on how you trade it and how you present it to them. If you are good in sales talk, you can make a high profit. Learn how to convince them to trade your bitcoin or altcoin. That is the first thing to do, learn more and more.
Yes I would also do that.
But in my opinion I would go for bitcoin to altcoin and keep doing it that way until you reach the quota that you are targeting.
There might be downs at start but with experience of doing it you will get used and know what altcoin could be trusted.
Though sometimes you could also profit from shitcoins.