It definitely not 100% safe, many exchanges had hack or scammed and people had lose their money so if you keep your money on exchanges be ready to lose it
If price is go down after the ICO, for me it's not a good sign maybe it's not that good project if the price go down it's not necessarily true but I'm beginning to think that way
if u wanna increase them than invest in some really good ICO or else hodl them for life they will make u rich in near future
Now find really good ICO is hard I think better for now at least is to hold, when ETH price will be on all time high then you can think where to invest