On that particular subject - advertising to donors that their money would be used for election security, but then using it for travel costs and rallies instead - legal analysts have said it probably isn’t criminal, per se. It clearly would be unethical, but since the donors were never promised anything in the form of a contract, but rather just e-mails or phone calls indicating that is how the money would be spent, there’s nothing legally binding to constitute criminal fraud. If individual donors wanted to sue, they might win a civil case, but that would be a different matter than a criminal charge brought by a prosecutor.
Criminal or not, it was not only deceptive, it indicates to me that Trump has no real interest in trying to clean up the elections, but rather has just used them as a talking point to generate more donations.
The bottom line is, how many Democrats and other Republicans have done the same thing, and no one batted an eye?