Reading your question again very carefully, I think I now get the gist.
1. Is there an easier way to get him into the UK than to marry him.?
2. If I marry him do I have to declare it officialy?
1. Yes, he can:
- bring loads of money into the country (not sure of current minimun - it used to be 150,000k and start a business and employ people.
- wotk visa - needs to be sponsored by a UK biusiness, job must be advertised in the UK and EU and company must prove that no-one suitable applied and that those who did apply were unsuitable and why, and why a non UK or EU resident is essential to the business.
- student visa - I think we can all assume things will have tightened up in that area pretty quickly after last week's events.
- family member - DNA tests required to prove relationship.
-visitor visa - must have return ticket and appropriate means of support i.e. enough money to cover period of visit.
- marriage - must apply from outside UK. If he comes here under any other visa and marries here - likelihood is that he will be refused leave to remain until such time as he applies from his own country.
2. If you marry him, you will have declared it offically. To lie about it or hide the fact may resulty in the immigraion authorities declaring it a marriage of convenience.
Don't go through with any marriage unless you truly want to be maried to this man, the repurcussions just aren't worth it.
I do speak from experience having gone through the process myself (a good many years ago)