This is a good value cage! Simple design but a nice long shape (why oh why do they still fix the perches lengthways? Much more flight space for the bird if they’re fixed front to back, plus the shorter dowels would mean less costs).
Be careful to secure the guillotine style doors to avoid any escape/trapping.
This is fine, but I’d choose the small size, not medium.
Great. Yes you should have cuttlebone too.
Treats: Treats are whatever the bird decides is a treat! If he likes millet then that’s fine, just don’t be excessive. Break off individual balls, one ball (or one nibble at a ball) is a treat and a couple of balls a day is fine but hanging a whole spray of millet in the cage isn’t.
I do like corner perches as I feel they use up an area of cage space that often goes wasted, however this ‘rack’ type version has the same issue as any other dowel perch - smooth, same uniform diameter perch that doesn’t exercise the feet. If you can find a solid platform version of this (eBay?) then I think that would be better. Platform perches are especially useful in offering a place for a flat foot position if you plan to put paper under the grate rather than on top of the grate.
Get a ruler and double check any measurements, this is going to take up quite a lot of space for a swing. It’s okay, but again, it’s a smooth dowel perch.
If you could find something like this https://www.amazon.com/dp/B01ER1EXQE...ing=UTF8&psc=1
, (have a look in the rabbit/guinea pig section of your local pet store) then you get a swing, foot exercise and a chew toy all in one (plus, if you push a ball of millet in there, then it’s a foraging toy too).
Rope perch. Yes, you just have to keep a close eye on any chewing & fraying. Again, I’d try to check the diameter to find the best size.
Bath. Seriously, I’d just save your money! Both my birds prefer an open dish rather than an enclosed bath. I usually use a terracotta plant pot base tray (nice grip on the base). You can always place it on top of the cage to use during out of cage time (benefit of a flat top cage).
Just my thoughts, hope they’re helpful