@Rainydayz179 - You can't play this way. Just pack it in, it can't be done. >:)
(I am, of course, not being serious yet) :p
I have 16 Traveler mod connected worlds in my six year old ongoing game, with several thousands of sims between them. I play five of these worlds where "my" sims live in rotation, and also leverage
NRaas StoryProgression's caste features to rotate through anywhere from 2-10 households in each of those worlds. The other connected ones are the WA worlds, Uni, Oasis, custom vacation destinations where my sims might have friends and vacation homes, and a couple where no one I play really lives there anymore but there might be some friends of the elders or some very distant relatives still hanging around whom I don't want to lose completely just yet. To some, this game of mine seems extreme. But from chatting with colleagues at NRaas and on MTS, I can say that I'm not the only one who plays this way. Some have ongoing games started in 2009 when TS3 was first released that they still play, some who play more often or much faster than I do or who rotate less are on Generation 150 or something, etc.
With NRaas Traveler, there is no hard limit to the number of worlds one can connect. But I don't know of anyone who has, say, 50 or 100 of them within the same ongoing game. Seems like the TravelDB file that holds all of this together might corrupt and things would maybe begin falling apart somewhere along the line.
Things can of course go wrong, even with all of the mod protection in the world this game is delicate, and there are times when I have to revert to a prior save in the single timeline to replay around something awful happening. You can call me overly cautious, paranoid, all kinds of names, I call myself these names in fact so it's all good, but I have easily over 150 copies of this game from different points in time saved on internal and external drives. The notion of losing the entire thing at once is just not tolerable to me, the only ways that can happen would be if someone broke into my apartment and stole all my computer equipment, the entire building burned down (reminds me, I really need to send a few of these saves up to the Cloud one of these days), or if I get clonked on the head and don't even remember what a sim is. Plus it's fun to be able to open up one of those now ancient saves when looking for or trying to remember how something worked or what it looked like back then, whatever happened to that great painting so and so made, etc.
If you told me back then when I sat down, created my first sim, and placed him in Sunset Valley that I would still be playing TS3, and that same game save, six years later I would have said that you were crazy. This was only meant to be a let's check it out kind of thing, if I don't like it I'll easily find something else to play. That...didn't happen. And none of this was really planned out in advance, it all just sort of evolved over time.
As far as safeguards are concerned, it sounds like you are already well on your way to doing what you can for your ongoing game. But there's two issues to separate out a bit -- Prevention and Recovery. The system of backup saves however one arranges it are for Recovery should something catastrophic go wrong with the in-progress game or the computer on which it is being played. It's easy to say when one has successfully arranged that, just look at the number of saves you can resurrect at any given time. Prevention is, of course, trickier and some of it is more art than science. We have a page full of performance enhancing tips at NRaas in case you haven't seen it that covers most of the things we do to keep our ongoing games from imploding on us. Feel free to ask for assistance here or at NRaas if any of that requires further explanation. :)
http://nraas.wikispaces.com/Tips+For+Better+Game+Performance