I like @horatio's answer, the common term for what you're doing is masking unwanted parts of the image, so it could be called a mask rectangle.
I tried to come up with a better word, but I think there's a deeper problem: what the word removed means. What does a button labelled "Remove Exclusion Area", "Remove Blind Spot" or even "Remove Ignored Area" do? To me it sounds like it will actually remove the area the rectangle covers from the image. It sounds like, no, what it does is remove the rectangle denoting what parts of the image are to be ignored.
That's why I would go with mask. It's specific enough to refer to what's doing the covering, not's what's underneath. "Remove Mask" should be understood in English, although I'm not sure how it translates.
You are right; but there is no general rule. Each verb has its own rule; the technical term is that each verb “licenses” complements of specific types. Refuse and decline, for instance, license either nouns or infinitives, but not gerunds:
I refuse dinner. I refuse to run. but not ✲I refuse dining.
I decline the honor. I decline to run. but not ✲I decline accepting.
Like, on the other hand, licenses all three:
I like Jim. I like running. I like to run.
Some verbs license multiple arguments, of different sorts or the same sort:
I made him a martini. I made him angry. I made him work.
In this case, the verb has different meanings with different arguments.
You just have to learn what arguments each verb takes, just as you learn which of your friends drink beer and which whiskey (or whisky) and which only water.
Best Answer
It seems to me that "Something wrong" is nothing else than telegraphic style for "Something is wrong" ("Something's wrong"), and so there seems to be a choice between two styles, or more precisely two registers; the question is then one of formality/technical communication; how formal do you want your text to be or how formal does it need to be? The choice is yours, once you know that a telegraphic style can be considered a rather technical or bench-level register, and that out of the domains where it is usually found, it can be felt as informal. Here is an article out of which you might get some inspiration: Telegraphic Registers in Written English - Stanford University. According to this paper there are several telegraphic registers, but Wikipedia does not mention telegraphic registers.