You ll be fine running cat6 over the insulation.
Cat6 in attic.
14 for 12.
Exterior grade ethernet cables are waterproof and can be buried in the ground without a conduit.
Rj45 jacks and plates get what you need maybe an extra or two.
Since the network cable will be run in the walls and the attic would code dictate that i use riser cmr or plenum cmp rated cables or will general purpose cm category 6 cable suffice.
In fact attach to your joists.
Remember that the main thing which defines this cable as cat6 rated over cat5 is the center insulation piece that.
Cat6 cable in attic in the attic i noticed i have some cat 6 cable wound up.
1000 spool cat5e or cat6 cat6 recommended more or less based on your need.
A wired cat 6 network is more reliable and secure than a wireless network or cat 5 cable network for your internet connections.
If you aren t burying the cable choose a waterproof cat 6 cable that has a uv protective jacket to prevent damage from sunlight exposure.
Single gang retrofit boxes the kind that clamp to the drywall open back.
A zip tie loop stapled to the joist could be a good support solution.
My concern wouldn t be heat related.
The cat 6 cable runs will follow the existing runs for cable tv coax in each room.
I can offer a few tips for those rewiring their house and using this cable in the walls and attic.
The end i can get to is cut for me to work with if i wanted and i am not sure where the other end goes to.