If he rolled that sun of a gun, when he put sod or seed down, you've found your culprit. An interesting quote from one of my lawn books was "There's more damage to lawns from mowers with rollers attached than from any other damaging source". If you run a roller over your new sod, or new seed bed, that roller should be EMPTY. That means NO water in that roller. Otherwise, you've compacted the heck outta that soil, and it may take years to heal. I recommend renting a power core-aerator: make two passes, in X directions. Obviously, let the cores sit where they fall. Those cores will break down and re-fill the holes. Do it in early fall (September, when the heat has broken) and again in late fall, when you're still reliably far from a hard frost (here in mid Michigan, that's a week before Halloween). In spite of some common recommendations to bag clippings if a fungus is detected, my advice would be to mulch mow, especially the first three mows after core aerating. I'd also recommend using Milorganite fertilizer this fall, putting down an application after each core aeration. For both techniques, the rationale is that you want organic material to fall (you don't have to go place it there, just let it fall) into the holes, and further, you want organic material, and all the little soil critters that come with it, to penetrate the thatch layer, which will keep the thatch layer at optimal depth. I say 'optimal' because too little thatch is as problematic as too much thatch. Many of the newly-seeded lawns discussed in this forum this year are not yet optimal, because the thatch layer hasn't developed yet: it will next year. I'd also spray a general purpose lawn fungicide, over the affected area. Now let's sum up: you didn't get enough Nitrogen down this fall, because you used Milorganite twice, and that's a low first number (6-2-0). Use Milorganite twice, next spring, to compensate for the nitrogen loss. We would 'normally' put down a big-first-number fertilizer in the fall, like a 18-x-x, or a 22-x-x, or larger. We'll go back to that next fall. This year, we want the organic material, and the iron, in Milorganite. I'd spray again, in late spring, the general lawn fungicide, over the area affected and sprayed this fall. And I'd core aerate, one more time, in the spring. I know it sounds like a lot of work. I think you'll see results if you do it that way. I fear you'll see spreading fungus if you don't.

I don't see anything here to worry much about. 1. The aphids and spittle-bug won't do serious harm, just wipe them off. 2., 3. Some scattered leaflets and leaves will just die for no evident reason. Ignore. 4., 5. The translucent windows are from rose slugs, small green worms feeding on the underside. Just wipe them off. Predators will often control them for you. Oil or soap sprays should work if you coat the worms, but wiping off is actually easier unless there is a huge infestation. 6. This may or may not be spider mites. Look with a 6x hand lens. Mites are normally found mainly on the undersides of lower leaves. I've only seen them on upper stems in the case of neglected plants grown indoors, especially in low wintertime humidity. It's possible this mini plant was infested when you bought it. Washing repeatedly with a strong spray of water will control mites effectively. Outdoor rains, humidity, and natural enemies usually keep them in balance. Use of chemical insecticides is the usual cause of flare-ups. Good luck. Sounds like you are a good, attentive gardener. The main things to keep up with are blackspot control and water.

Where the leaf is stripped is definitely a caterpillar eating....the brown spots, I'm not certain. The small black flies lay larvae that make trails through the leaves (leaf miners), but I don't see evidence of those. Cabbage worm eating tomato plants sounds a bit like tomato fruit worm...you can Google for an image. You can pick them off, or if they seem to be out of control, you can try a BT spray. I am sure someone will have an idea about those brown spots.....

I listened to the video a few times. I couldn't confirm the popping was from the intake, but it sounded like it was. If it were mine, I would remove the inline tank filter if it has one and verify routing of the kill wire. Since you swapped coils, I assume that the wire ends were also swapped. But it really sounds like a sticking valve yet. What is the history on the mower? Has it sat? If varnish is present on the stem, the official Honda way is to heat the stem. Could it be a loose baffle in the muffler? I've not ever see one. If something else comes to mind, I'll give a shout.