Doesn't look like bugs. More likely a bit of fungus from being a bit too moist close to the soil. Doesn't hurt to look closely for bugs under the leaves tho any time you see spots just in case. Especially with mites as one or two can be dozens a week later then 100s a week after that. They leave little white/yellow spots randomly all over the leaf surface. I'm just getting over a nasty mite infestation and you don't want any of that!
Deficiencies or nute burn affects more than one leaf at a time and I've seen a lot of plants in trouble because people are too quick to start tossing more stuff in the mix trying to fix a non-existent problem.
I wouldn't cut off the leaf unless it seems to be spreading. Make sure you have good air movement that includes the base of the plant so moist air isn't trapped around the base and you should be good. Stem rot can happen too and that will kill a plant dead!
Plant looks really good otherwise.