The answer to all of your questions here is 'yes'.
The Sabre is currently available because of the Anniversary Sale, and will be through to the end of it, and the Cutlass is always available for sale, so you should be able to repurchase both afterwards. The only thing to bear in mind here is that you must wait 24 hours after you purchase your Vanguard (whether with cash or store credit) before you can melt that purchase. Afterwards you will be able to use the store credit from that to repurchase some Hawks to use as LTI tokens, and then to purchase CCUs from those back up to a Sabre and Cutlass. (However, if you purchased Warbond Hawks, then bear in mind that you can't use RSI credits for those, and the non-Warbond version that can be purchased with RSI credits are more expensive.)
One other thing:
Aside from the complaints about the current Vanguard's model vs. the original concept art (and these complaints are valid, IMO), I would argue that 9/10ths of the Warden's bad reputation in 2.6.3 is due to its terrible handling. This is because of what almost certainly amounts to a typo on the part of some Dev over at CIG with regards to some of the Vanguard's flight model settings. (Seriously, the flight model numbers responsible for that bad handling were so outrageously low compared to any other fighter in the game that it's difficult to believe it was anything other than a simple mistake that no one caught until after the patch had been pushed to Live.)
Anyway, my point is that they seem to have corrected this in the current PTU build for 3.0. The Warden is still not very maneuverable compared to fighters like the Gladius, the Sabre, or even the Hornet (it's about as maneuverable as the Cutlass, actually), but where in 2.6.3 it feels like you're constantly having to wrestle with the ship's nose to get it to point where you want, in 3.0 its handling is now very precise and easy to control. Where, in 2.6.3, it felt fat, heavy and slow, in 3.0 it feels big, powerful and dangerous.
Combat in 3.0 is still way too buggy to really test anything out, but my current impression of the Warden is that it will be making a pretty serious comeback as a top-tier dogfighter in this patch, especially as genuine multi-crew and turret gameplay become available.
I hope all that helps. :slight_smile: