8' is a very short hammock and a ridgeline will be very low and in the way when sitting. If it doesn't suit you, just don't use one. Their only purpose is to set a given sag to aid in setup and to hold a bugnet up in some cases.
The tarp and hammock suspensions touching is acceptable. There are a couple of ways to set it up where they don't if you want to try them. To me, it's more trouble than it's worth.
Happy hanging...I hope you get it all worked out soon.