Here is someting that is really crucial in how hard it screws over highsec:
Combine this with the reduced defences and only having 1 timer that will follow the above rule.
Most groups will get started with just 1 structure and it’s going to be a medium structure as that is the most affordable and it used to be the least interesting to specificly target for effort vs reward.
Having 1 structure means it is automaticly the war HQ. With these changes a wardec could be made on Thursday, the shield attack on Friday and before Sunday is over, the structure is gone. Meaning that at best there is a 72 hour window after the wardec in which the defenders need to have organised themselves, get help and coordinate with allies and hope they were able to gather intel on what to expect from the attacker. Not to mention that there is a extremely limited window in which things can be moved out of the structure or things are locked behind asset safety.
With regard to the timer and response time its effectively exactly the same situation as in Wormholes and for wormholes it is considered to be too harsh.
Not to mention that the attackers tend to just go after highsec structures for a quick buck or easy content/killmails. With these changes a lot more structures will suddenly become interesting targets because it yields solid rewards for the investment in time, effort and warcosts and a lot more can be earned in a shorter amount of time.
It’s going to be a short goldrush for very specific groups but leave a more barren game with fewer players wanting to keep playing and that will hurt everyone within the game.