I recently visited a couple of old questions that I had posted and there were a lot of edits (mainly grammatical but not all) that I wanted to make. I edited a couple of them and went back to the homepage and the homepage had all of these edited questions on it. It seemed like a disruption in the natural working of the homepage. How should I go about it? Should I leave it on the system to realize that it shouldn't flood the homepage with the dozen old posts I choose to edit in half an hour? Or should I refrain from going on an editing spree?
Yes, you should avoid flooding the front page. I recommend doing them in small batches of say 2 or 3 posts at a time.
If you really want to go on edit spree, you could reduce disruption by editing recent posts alongside with your own. If you commit yourself to improve 2-3 recent posts before you touch another post of your own, the disruption will be much less harmful.
It would be even better if you take longer breaks from editing, either by doing something outside the site, or going through a review queue or writing a new answer to an old question.
I think the answer really boils down to how you answer the following question:
Do the changes you want to make improve the readability or accuracy of the post, or is it just superficial changes?
If it's the latter, don't worry about editing it then because no one will care/notice ever.1 If it's the former, then you are probably fine to make the edits, depending on the quantity of edits you want to make.
That is, if you want to improve say 2 questions on main, I don't think anyone will mind. If it's closer to 10 (or even beyond!), try spreading it out over a several days/weeks.
If you're looking at old Meta posts, you really need to be considerate since it takes a long time to move off this page (I currently see a post edited on Feb 5 at the bottom of the page; on main question at the very bottom was last touched 5 hours ago). I would be very wary of making changes which are not large/significant improvements to the post.
As mentioned in the comments, we do have an FAQ on titles that says in item #6 to not capitalize every word in the title, only proper nouns and the first word should be capitals. So if your goal is merely to change the capitalisation scheme (as was done for a few of the updates by OP on Meta) to Capitalizing All The Words, don't. Just leave it and worry about factual errors.
As a last note, when you make your edits, please do not makes your post look like a revision table. Don't add "Edit $n$" anywhere in the post, instead you should seamlessly integrate the new material in the original post. All SE posts are version controlled, so interested parties can just check out the diffs if they're so interested.
1. Of course, if someone else has added an answer or edited the post, so it's already on main page, I think you should be free to edit it as needed.
In my opinion, improving the content of the site is more important than worrying about what's on the front page. If you want to edit, then edit.
So what if your questions wind up on the front page? They won't be there for long anyway, and there's nothing wrong with old questions getting attention.