I've got about a dozen tomato plants of different varieties in containers on my northeast-facing deck (mid-Atlantic region of the US), which receives about 6 hours of direct sun exposure per day. Some of them have developed these black splotches on their leaves. Based on these articles on Southern Living and Old Farmer's Almanac, it looks like this might be a sign of Septoria leaf spot. Is that what this looks like to you all as well?

EDIT: Clarified orientation and daily sun exposure.

Transplanted my tomatoes into 7-gallon grow bags on Sunday of last week (8 days ago).

• DIY potting mix w/ approximately equal parts store bought garden soil, peat/coco mix, and compost, w/ a few handfuls of perlite and a touch of granulated all purpose fertilizer mixed in.
• Mid-Atlantic region of the US (zone 7). They currently sit on my back porch, which faces northeast and gets about 4 hours of direct sunlight per day before they're in the shade. Weather has been mostly sunny w/ highs in the upper 80s to lower 90s.
• I watered them right after transplanting plus two more times since then (no fertilizer, just straight from the tap or hose), so about every third day.

Is this transplant shock or do I have some other problem? I've tried following this guide (Why Your Tomato Leaves Have Brown Tips), but since the brown tips affect all the leaves (oldest and youngest), I'm unsure of the most likely issue, so in the absence of a clear indicator I'll likely just keep doing what I'm doing and hope for the best.

Thanks in advance!

EDIT: Clarified some things and fixed a few typos.

History:

• May 4th: The marglobe tomato seedlings in the photo were sown indoors in 12-cell grids, two or three seeds per cell.
• May 18th: They all had their first set of true leaves, and they received their first "indoor" dose of fertilizer using Miracle Gro water soluble all purpose plant food at a concentration of one-half teaspoon per gallon of water, which should produce a ratio of 3-1-2.
• May 19th: Their seed leaves had turned yellow, but their true leaves still looked normal.
• May 23rd: Most of the seedlings were looking pretty sad (wilted, drooped over), and the soil was looking pretty dry, so I gave them another round of watering, this time with plain water (no fertilizer), and within hours they were back to looking happy again.
• May 26th (today): Back to looking not normal but in a different way. Many seedlings' true leaves are folded upward, and the two seedlings in the front-right cell are wilted and drooped over again. I gave them another shot of plain water (no fertilizer) this morning since the soil was looking dry again.

All waterings, including today's, have been bottom waterings, where I lift the cells out and pour water into the bottom trays, then dump any excess after about 10 minutes.

Questions: Did I give them their first feeding too soon (at two weeks old)? Are seed leaves' yellowing and true leaves' folding upward a sign of nutrient burn? Should I flush the soil w/ plain water to flush out the fertilizer from the 18th?

EDIT:

Looks like my azaleas have lace bugs and mites. They need to be trimmed anyway, so I'll give 'em a haircut and go from there. Thanks for everyone's input.

ORIGINAL POST:

Row of azaleas on the northwest side of my house (mid-Atlantic region of the US). We've had some rain, but I have not watered them manually at all since I moved here in the fall of last year. Previous owners were far more attentive to their plants than I've been, but I'm looking to make amends. These azaleas have mostly green foliage w/ patches of purple leaves and/or bare branches. Should I be concerned or is this typical of azaleas? Are they underwatered?

Close-up of purple leaves: