hi,

most of the time, no but that just makes it more of a challenge to get
contacts.

if you want DX, you'll need horizontal polarized antenna for ssb/cw
and vertical polarization for FM.

Sure, you can use vertical for ssb/cw BUT you loose 20db from polarization
error.

Higher is better !

here is link for you

http://6mt.com/

good luck on 6 !