Hi vally
Some hugsss for you. I tried cooking our own food at the first 2 weeks and got so frustrated and tired. We only use jarred foods. DS loves it. They are very tasty and no additives, salt or sugar. I don't see there is anything wrong with feeding LOs with them. But I can see one down side, the food for older babies, here from 8months, there are so many ingredients in one jar, I don't have a choice of what's in there. I think if you have worries about allergies, then be cautious.
About the lumps, perhaps your LO is just not ready for texture yet. Let him take his time but do keep trying. Then he gets to learn.
Good luck and HTH