Holding bitcoin is better but at the same time if he start trading with that bitcoins then he will increase his income more higher, he should have to buy and sell some altcoins also and if possible then have to hold some altcoins, like LIR, he will get it a more beneficial investment.
Both s good. Holding a little bitcoin for savings but also use your bitcoins to invest in new ventures.
My guess is that if you do both consistently you will be able to get a decent amount of money from your investments.
I think investing with bitcoin might not be a good idea. No other investment will be better than the bitcoin.