no but there's a part of the app that asks where else you applied to. Ive heard advice you should include a couple of but not all the schools. But it really isnt all that important
I don't understand why you need to explain the first... It sounds so ridiculously minor that I've never seen an app that would require it. I'd send the LSAT addendum but I wouldn't send the other.
... the employment history in the app as completely as possible for ... of thumb across the entire app). And don't have anything ... don't put in the app.