yes, it's better for you to store it in your own wallet than in a wallet exchanger because it has a fairly large risk
for a good coin it looks like you have to glance at Doge, usually doge is used for bag holders and can make you gain a very large profit
It's okey. Probably you have invested in those coins for staking. It is both staking and profits as usual. I prefer TRX holding than other coins as TRX gives more staking rewards than others and TRX has much chance to boom in the near future. It means TRX holding will give two facilities-staking and profits.