Jim,
If you follow the 'normal' rules for using twin-
lead feed line you shouldn't have any more (or any
less) problems than if you used coax. There is always
the possibility that RF will 'eat up' all the electrical
appliances in your house, but maybe not.
Nothing except your pocket says you can't change feed
lines or antenna if you want. So, try it and see what
happens...
'Doc