Even investing in mining right now isn't profitable, and cloud mining pretty much never is. Most things won't be affected by the halving though, so you could try some things that work now, like buying something and reselling at a higher price, lending or things like risk free gambling (either promos or arbitrage betting). How do you make Bitcoin now? Chances are, it will still work after the halving.
Cloud Mining is definatly profitable. What are u talking. Its just an order of time. To be sure try to invest after the halving. i dont think cloud mining will go down cause the btc needs it

The Transaktion speed could decrease unless it would never fit to the blocks which would increase the fee and the price i think.