Animation Novice with a few questions

Hello,

Im fairly new to animate, but I've found myself in a position where I am using it all the time now. 

I'e spent the last few months using it and I have learned alot. However there are some ways I am doing things I have questions about.

I draw a character, convert everything to symbols, rig it up and save it as a "main puppet". Then anytime I want to use that character in a scene I make a duplicate of the main puppet specific to that scene and I animate that.

Then I make a walk cycle, and I save that seperate of the puppet. 

So anytime I want to make a character walk from a standing position I have to resize the walk puppet and cut the main puppet out and put the walk cycle puppet in (you get what i mean).

I feel like I am probably not doing this right, Im guessing I can probably nest the walk cycle within my main puppet and just use it that way? Ive done lip syncing and nested symbols but im not really sure about how to nest the walk cycle. if I can even do that. I hope this makes sense

Also, I just experienced a file corruption and lost a days work. Id been saving different versions of my file and I figured out I should be doing that more frequently.

Heres the thing though. Im doing a series that has episodes and I have up until this point been doing multiple projects (episodes) in the same .fla file. So now I have an .fla file that has lots and lots of scenes and all my assets in it. What I am wodering is if I should be breaking my pojects or episode into their own .fla files and importing assets as I need them from a master file or something?

I hope this post makes sense and any input or advice from someone more familiar with this would be very much appreciated.