I'm not being negative guys, just asking the questions to understand. Less difficult alt coins are even cheaper, i buy 1 LTC and exchange to those, will get heaps of each.

The problem is: to secure the coins against the exchange's CEO stealing everything, I will need to download the block chain of each alt coin. This has to be on a very fast SSD, minmum 1 TB for all the coins. I could safeguard each wallet.dat and delete the wallet, but that means I can't buy again more of that coin unless i reinstall and download the block chain.

Everything seems easier than mining 24/7.