Illegal things are what society uses to judge behavior. If it is illegal the morality of that behavior is suspect. If it is a behavior that everyone does, it isn't something that we should be used to criticize.
When it comes to the offshoring, everyone does it and something similar i.e. take advantage of the laws to their benefit like tax breaks. I don't see how that is a valid criticism when everyone does something to the same effect. It is a very small minority that willingly pay more than they have to and we shouldn't use that minority as the base to decide scorn because we should nearly all be scorned.
Really, aside from the Trump foundation thing, the things you listed weren't illegal things that everyone in that position does. At least he says he uses it (letting everyone know people like him get that advantage) and he wants to change that (which is a promise that evaporates faster than a fart in the wind butts aside). There are plenty of things to criticize things Trump for and using behaviors that everyone does (take advantage of the laws to their benefit) that is not illegal that the law was set up to be used is not a good basis to lay criticism.
The difference between the offshoring and the " a politician using their position to be good bed fellows to big business " should be apparent besides the legality. It is everyday that business use offshoring because of free trade and globalization. It should not be every day that politician use their position to be good bed fellows to big business.