1. "Please///NOTE that the project was suspendED for a long time, and our auditor asked for a budget revision.
It seems that the correct time here is simple past because of simple past in the verb "asked". But, this sentence could also use present perfect: "please NOTE that the project HAS BEEN suspendED for a long time, and our auditor HAS asked for a budget revision."
2. The project is suspended. This is a suspended project
Yes, these are both correct and possible. You could also have "The project HAS BEEN suspended.
3. The job WAS suspended a long time and resumed last month.
4. This is a SUSPENDED project.
Don't forget that things can only have -ing participles, while people usually have -ed participles.