Some great ideas there!
Im really all for the no griefing offline thing, the ONLY times my bases have ever been attacked were when i couldnt defend, thats a crappy feeling.
I do think though that there needs to be a perhaps 10 minute period before the effects kick in so insta logging wont be such a good strategy.
For PvP, there needs to be some medium range tracking ability so that you can actually track other players, the map of this game is HUGE and you could go days without seeing someone, i think one of the major issues players will face is that its too difficult to force pvp.
on a seemingly contrary note, i really hate the gameplay of stacking wooden frames 50 ft high to jump over walls, perhaps a height limit for areas near land claims would be a huge help? id love to see more open bases that dont necessarily need to rely on capped roofs to stop perps.
One different issue would be restarting after every spawn, id suggest letting players keep whatever is in their actionbar and add in a new perk that respawns you with some basic armor at low quality (half of what you could create) and clothes (just feet, chest and legs) for instance:
level 1 respawn with plant fiber clothes and a wood breastplate
level 2 respawn with cloth chest armor and some cloth clothes (just feet, chest and legs)
level 3 respawn with leather chest armor and cloth clothes
level 4 respawn with scrap chest armor and cloth clothes
etc
other than the scummy base raiding, the pvp in this game has made my pulse run like mad, the high risk high reward makes it feel amazing! though when you lose you feel like dying, it really has the highest highs and the lowest lows