What I meant about point 2 is that precisely because the strategic reserve cannot be gamed to leave the HW, while you can't touch the ai HW's which just your BB, you have almost free reign on the rest of the galaxy.
Since you need so much micro on the nebulas, it is far better to let the ai launch ineffective offensives against your bolstered super HW enhanced by nebulae so you can focus on nebulas. Sure, you can't hit the HW's themselves, but is that so bad if you have the rest of the galaxy free to plunder?
It seems that if you want the BB, you want weak offensives so you are not distracted in nebulae. This may or may not be desired. For sure there is a very real benefit to having the AI be able to have a super great HW defense force, but being unable to defend the rest of the empire due to your massive champion + controlled allied force crushing any source of resistance. Maybe this unique siege tactic should be allowed, much like FS allows you to deploy a hammer to smash the ai into submission.
In the current game setup, if you purse the BB route, you follow nebulas till you get BB's, then its just a matter of getting the right golems, ars's, and spirecraft or FS to conquer the HW's. The game almost leapfrogs from early game tactics to late game tactics. This may or may not be desired.
EDIT: I am almost asking that it is OK for the player to lay siege to the ai homeworlds with the champion and its forces. Is it OK for the player to lay siege to a ai HW? Sure, its a castle that you cannot hope to smash immediately, but you can pillage the ai country side to your content. The idea actually is warming to my heart, so I'm not so opposed to it. I'm just asking if others like the idea as well.