If you are talking about single spd setup, main problem, as mentioned is good chain line. The more angled the chain line is to the CW or rear cog, the more likely you are
to derail the chain. If you are talking about single chain ring and functioning RD/cassette, you have the same problem which can be partly ameliorated by retaining the
FD and using its cage to reduce the risk of derailing the chain from the CW. Bolt on outer chainring guards and inside chain keepers can also be used for the same result.
No reason you can't use the original 34t compact CW if you keep these parameters in mind.