I processed tomato sauce last night and 2 lids weren't sealed in the morning. They all seemed sealed last night.. Can I safely reprocess them this morning even though its been 8 hrs that they sat and cooled?
Based on what you've told us, you should be just fine. Straight from the USDA's Guide to Home Canning (page 1-26, emphasis added is mine):
[If a lid fails to seal on a jar, remove the lid and check the jar-sealing surface for tiny nicks. If necessary, change the jar, add a new, properly prepared lid, and reprocess within 24 hours using the same processing time. Headspace in unsealed jars may be adjusted to 1-1/2 inches and jars could be frozen instead of reprocessed. Foods in single unsealed jars could be stored in the refrigerator and consumed within several days.]
I am assuming, though, that you used a recipe for canning tomato sauce, and followed it. Oddly enough, although we think of tomatoes as acidic, they are sometimes not acidic enough for canning. Because of this most tomato sauce recipes for canning call for lemon juice or citric acid.
Because the jars didn't seal, you don't have an anaerobic environment, so you wouldn't have botulin toxin. However, because of the cooler temperatures during the time the jars were unrefrigerated, you might have other microorganisms growing. This is where your 40-140 rule comes in. The best environment for growing unwanted stuff is when food is between those temperatures(2). This possibility would be why, if you aren't going to reprocess, you should recook and refrigerate if you want to consume the sauce in those unsealed jars. You could also freeze the sauce after recooking.
From my personal experience, I have had stews with grains begin to ferment, because they spent too much time cooling down in that danger zone. Interesting - but not an experience I want to repeat. I have also had home-canned low-sugar jams ferment because they were treated like commercial (high-sugar) jams (meaning they were left out of the fridge). I don't want to repeat that either.
: https://nchfp.uga.edu/publications/usda/GUIDE01_HomeCan_rev0715.pdf (2): That is degrees Fahrenheit, by the way!