i think is we can not handle too much coins, its better to handle 5-10 coins in the same time because if we have more than 10 coins, its can makes us too confuse to watching the movement of each coins. I am telling this because I have experience with this in the past and I don't want to do the same thing again. I'd rather handle few of coins so I can focus watching the market.

for going short term you can go with bittrex because in that site I see many pumps and dump in short time in a day and if you luck and you can watching the movement, you can make a big profit. waves still on the way and many people buy this coins, but its up to you, the choices is yours.