How necessary are the bow/stern tie downs?...
How necessary are the bow/stern tie downs? I'd like to use it without them if I can, as they may be another hassle. Driving around town should be fine, but how about highway?
If you can get the straps to the hull raisers tight enough you won't need the bow/stern tie downs for short trips even on the highway. But if you are taking a longer trip I would use them for safety.
The included tie-downs are designed to be easy to use, no need to tie knots, etc. Getting them attached to kayak and car is pretty simple, so you might as well use them. If you do not use them, you can still get the kayaks secure enough for low-speed transport for sure.