I'm no expert, but look up early blight. I'd remove the leafs

I have a similar problem and am using this recipe with some success: 1 bulb garlic crushed, 1 onion crushed, 1 Tbl cayenne powder, 1 Tbl liquid dish soap, 1 quart of water. You can spray or just splash/rub it on the leaves by hand. Many find that a mild dish soap solution alone will work. Good luck!

Yes, the plants bounce back, provided the aphids haven't transmitted a disease. Tomatoes are very good at recovering from physical trauma. I would prune off any seriously damaged foliage. New growth will happen quickly. As for guarding against pests, it depends on your philosophy. Are you someone that doesn't tolerate any plant damage at all? Are you more holistic? Organic? What is the environment the plants are growing in? Do you have an established population of good bugs, i.e., predators that eat pest bugs? Personally, I think that good cultivation practices like not overfertilizing your plants (plants that have had their growth pushed too far by high-nitrogen fertilizers are more attractive to pests), keeping garden plants away from overgrown, weedy areas that are likely to harbor pests and diseases, and nurturing beneficial predators, are important. But other than that, prevention through chemicals and application of products is just more fuss, time, and toxins put into the garden. I have a good balance of beneficials, so I just stay vigilant and inspect plants daily, especially the undersides of leaves, and take care of any problems if and as they arise. If I see a few aphids here and there, I leave them for the beneficials. If I see them starting to really colonize part of a plant, though, I deal with them. If a problem occurs that can't be taken care of manually by picking off pests ((infestation of flying/jumping pests or pests like caterpillars that can wreak a lot of destruction very quickly), there are many options from relatively nuclear options to various organic options, to turn to, depending on your personal philosophy. Disease is something else. If you are in an area that reliably gets fungal or bacterial disease issues, preventative spraying of fungicides on a regular schedule is a key tool in keeping your plants healthy longer and slowing down any diseases they do get. As with everything else, there are more hard-core options and more organic options. Some people choose not to spray until they see signs of disease. I personally think that, in any area with appreciable humidity, tomatoes are so prone to so many fungal and bacterial problems that preventative spraying is a good practice unless you are philosophically against it.

I'm only going by what NCHFP recommends and that is that it is difficult if not impossible to remove most of the bacteria and fungus spores with the average soapy washing. So we are strongly advised against consuming those foods that are known to be contaminated without cooking them well first. It is a common question in food preservation circles, especially with potato skins and late-season tomatoes. Personally it seems rather UN-health oriented and defeats your stated goal. But that's JMO. I prefer to grow my own food because it is cleaner and healthier than most store bought food. So why would I want to consume food that I know for a fact is diseased or contaminated? But ultimately it is up to you to decide how much bacteria you choose to ingest. Dave