When wrapping the guides can it be harmful to the blank to wrap them very tight?I realize there has to be some movement for minor adjustments

Yes it can be. Thin walled blanks can be fractured by tightly wrapping guides, particularly if the guide feet aren't absolutely flat in order to distribute the pressure over as large an area as possible. Don't wrap them tight, just snug, and let the finish at the guide feet "shoulders" lock things in place.

.........

FLAT from toe to heel. Nicely curved from side to side, like a semi-circle, to match the rod blank's diameter at the place of mounting. You don't want a flat side-to-side cross section, but a curved one, Bill. ... The toe-to-heel flatness that Tom mentioned is to avoid a bridge effect, where all the stress is concentrated at either end of the bridge - guaranteed trouble in that case. For hand shaping, a flat mill bastard file will take out the bridge, and give a flat toe-to-heel axis. And a round rat-tail or round chain saw file will give you a nice arc from side-to-side. -Cliff Hall+++