Yes!... I would say "were", rather than "was" in the last sentence. This is the "subjunctive". However, in common usage today most people would just use "was" - so it cannot be considered incorrect. Maybe I'm just a bit old fashioned about this usage... ;

I might come over or I may come over. Use "might" if it isn't very likely and "may" if it is likely. Also might is used as the past tense of may. Also, you could say "Maybe I'll come over tomorrow if... Sometimes I ask myself (wonder) if I'm worth anything. Last sentence I would replace "was" with "were" although both are understood.

I'd say "Maybe I'll come over tomorrow if I finish my work here" (I'm not sure of the context of the sentence but I assumed you meant tasks for a job when you said job and that's why I changed it to work, correct me if i'm wrong). I replaced 'might' with 'I'll' because you've already said maybe, so you don't necessarily have to add the might. BUT, you are still right, I'd personally only use it to express something I'm really considering/unsure about. For example, "Maybe I might go to the party in the end' or "maybe I might give it a try" but I'd say 'might' expresses further uncertainty. Maybe I'll come over tomorrow if I can get a/the day off. 👍🏾 And these, Sometimes I ask myself If I'm worth something. 👍🏾 If there was something I could have done about it, I would have by now.👍🏾 Well done!

(a family visit etc.) Maybe I might come over tomorrow if I finish my job here. Maybe I might come over tomorrow if I can get a day off. And these, Sometimes I ask myself If I'm worth something. If there was something I could have done about it, I would have by now ___________________________________ The first two sentences should be written without "Maybe". The last two sentences are correct. I might come over tomorrow if I finish my job here. I might come over tomorrow if I can get a day off.