If there's one argument I hate, it's the "I rarely use them so I don't upgrade them" argument. Hogs aren't usable at TH8 for 3 star attempts until they're level 4 because they don't have enough hp to survive a giant bomb with enough of a grace to pre heal properly.
As for your walls, here's what I'm in the middle of:
Finish lab at TH8. Get to TH9, drop queen, gem spell factory, start upgrading camps. Use gold for the new air defense and new tesla, all excess gold goes into the wall. Don't build any new defenses until all 250 skulls are done. Upgrade your queen to 5, loons to 6, and then hogs to 5.. Then focus on golems to 4. When you have level 4 golems and a level 10 queen you can get away with plopping down the xbows.
That way should make you both harder to three star without affecting your war weight too much, and keep your offense at a higher level than your defense as long as possible. If your golems are level 4, and hogs and loons are maxed, you're ensuring that the rest of your troops are going to live as long as possible and you can take out the backend defenses as fast as possible.
1.5 months? Lol no, it took me 4 months at TH8 and that's considered faster than usual. TH8 is one of the worth THs to rush. If you don't max things now, you will never find the motivation to do it at TH9.
Early TH9 | Level 99GG: 367m | EE: 300m | HH: 811k | SOW: 40mWar Hero: 344Walls: 29/250 Legos
BK: 10 | AQ: 8
Why do you want to rush? For clan wars or faster base progression with minimal usage of gems?
My reasons of rushing to th9 are clan wars and heroes as high as possible without gems.
If you like idea of rushing to th9, better do it as early as possible. Prioritize heroes and war troops certainly helps a lot, after your primary farming troops of course.
I hang around 950 cups with a TH7 account. I barch TH7 bases with 200-250k gold every 10 minutes (mostly collectors, core if necessary).
I'll continue doing that when I am TH8, until I have all skull walls.
DE will be better at TH9 when you can get into the core of TH8 and TH9 bases. But if it is gold you are after, barching TH7 and TH8 bases is king, and level 5 or level 6 barch makes no real difference.
TH12, BK61, AQ 63, GW35, 5960
TH10 perma (?), BK40, AQ40 -- TH11 defenseless BK48, AQ50, GW 20 -- TH9 backup
22 days is not a problem because you still have a ton of stuff to do. I would stay at TH8 at least until you have done all the DE upgrades in the lab. You are done with your king which means you don't need DE for anything else. You have 50 levels of hero upgrades for TH9 so you don't want any leftover DE lab work from TH8 (leftover elixir lab work is fine). Since you have tons of elixir I would get all 6 of your barracks fully upgraded. You don't have anything better to spend elixir on and you will benefit from the increase troop storage capacity (you can hide elixir in your barrack's training queue) and the ability to make any troop you want from any barrack or dark barrack. The buildings also get increased HP so you want to do it eventually and you may as well do it now while elixir is plentiful.
When I was TH8 I stayed in crystal 3 and just barched. I never went out of my way to get DE (I wouldn't even attack drills that were behind 1 level of walls that could be easily hit with archers unless I needed the drill for 50%). The reason is that it is quite easy to get all the DE you need at TH8 will almost no effort (you don't need much). Focus on doing just DE lab work to get those upgrades over with and other than that don't focus on DE. Don't go out of your way to attack bases for DE. If you find yourself getting capped on DE too easily still then donate DE troops or attack with DE troops (Valkyries are amazingly powerful).