"ALL INFORMATION RECEIVED IS ANONYMOUS AND WILL BE USED FOR A UNIVERSITY RESEARCH."
Anonymity for respondents may be routine research methodology, but anonymity for researchers is suspect.
Requests for assistance without identification is merely rude.

Because you have used the word merely, the sentence means it's no big deal and it's quite alright to ask for assistance without identification. Be careful selecting words. What about this? This would be okay:- 'No that's no problem, i merely wanted to know if you were coming too'