New Hampshire: I hope I can answer a few of your questions but will have to leave the chambering questions and those regarding rebarrelling of the M1 Carbine to those more experienced and knowledgeable.
The Charles Daly actions are built on the Yugo M48/48A actions which are built to handle the 57mm length cartridges and are a bit shorter (1/4" I think) than the longer M98/VZ24 actions. They may handle the longer cartridges based on the 06 case and would handle the 55mm length of the 6.5 Swede (or the 7.5x55 Swiss) if the case head on the 6.5 was the same as the 06/308/7x57/8x57 but the 6.5 Swede's case head is a bit larger than the others and the bolt face may need a bit of reworking to get proper functioning.
Also, a turned down bolt doesn't mean you are going to get any scope clearance. The turned down bolts I've had needed to be cut and welded, ground and polished and I still had verrrrry little room to properly activate that military bolt even when I had a scope (even with a small eye bell) attached. With turned down bolts you usually have to mount the scope with tall mounts which may not be the best arrangement for quick target acquisition. I think a better idea might be to obtain a VZ-24 action with the straight bolt and to either have that bolt cut and welded as close to 90 degrees downside as possible or to get another bolt handle from Brownell's and to have that welded at a significant enough angle to give you lots of bolt/scope clearance and room to maneuver your hand around the bolt handle.
However, if you want to build yourself a 6.5 Swede, why not get one - either a M96 or a M38 and have that worked. You may even wind up saving yourself some $. I found my M38 to have a #1 barrel (best there is on the Swede milsurps) and before I had my custom work begun made sure the thing would shoot 2" or better at 100 yds with its open sights. Then, once it was finished, with scope and all, she was shootin' snake-eyes at the same distance and better. I think that in comparison my total costs for customizing (actually, sporterizing) minus the costs of an overly expensive stock, were less than what it would have cost me to start with an action, then a barrel, then the (necessary) action work, etc. Also, let's not forget an aftermarket trigger assembly and the Bold Triggers are very nice for the Swedes. So, there are ways to get what you really want without killing your wallet, and getting what you want so you can go for a total re-custom job later. That way you could use the VZ for your caliber change choices to the 06 case family later and still have your 6.5 (doancha just love it).
As for the bluing - I would get it all done at the same time - seems to match up better.
Re: the M1 - they can be rebarrelled in the original caliber but since it would be most likely with a mil-surp barrel, why not try to find one in good shape and good working order. If, however, you want to go to a custom caliber, like the 5.7 Johnson or some other caliber, then rebarrel but, the carbine is limited by its action and magazine length so you don't have a lot of room for change with that one. I think that if a carbine came my way I would leave it as it is and just have fun with it rather than try to do anything on a more serious level.
I apologize for the negative news (or ideas) and hope I haven't dampened your enthusiasm for your projects but do hope I have managed to provide some measure of help and insight. This be Mikey.