They ask you to park in front of the hotel. We always parked back in the hotel behind the automatic gates. The parking lot is lit, but is not "secure." Even non-hotel guests can drive into the lot for access north and south of the hotel at any time. I have stayed about 25 hotel nights at the Radisson for work - my job brings me there somewhat often and I have family in Cocoa Beach). I have also left my car there unattended for an additional 21 cruise nights (that was vacation) without incident. I intend to park there again this June.
The hotel is very busy, most days. There is security patrolling the premiesis, but a determined thief or vandal would have no problem.
The port parking is more secure, and guarded much of the operating hours. It is not guarded 24/7, and the there have been very infrequent occasions of thefts from cruise parking, and vandalism.
You would have reasonable security at the Radisson, more security at the port. The bottom line is don't invite trouble... and remember why you buy car insurance.