Well besides cheating
HT on increases your logical cores from 4 to 8.
It can be a nice boost for programs that do good multithreading, your rendering may benefit from having HT on, even running at lower clocks than you can hit with HT off.
About coolers, the Noctua D14 is massive so it might block tall RAM, but its a top air cooler.
The H80 is probably the best AIO sealed loop cooler(after the H100 with its bigger rad).
Either the D14 or the H80 cool about the same. One downside to the Corsair Hydros is they have no fans at the socket, so parts on your motherboard like VRMs don't get airflow like they would from an air cooler like the D14. The Archon is another air cooler to consider for its narrower footprint(but its quite tall), also the Supermega is fairly slim and cools similar to the others.