Can the deaf get a pilot's license?

Yes, but with strict limitations if the applicant is profoundly deaf (cannot benefit from hearing aids).

They are not permitted to conduct any flight which requires the usage of radio.

The link below is to the FAA which regulates flying in the USA, but most regulators worldwide have very similar regulations. The FAA allowance for limited commercial flying of crop-dusters is something which many other countries would not allow.

https://www.faa.gov/pilots/become/deaf_pilot/certi...

You could certainly get a private pilot’s licence in the UK (as I have done though I wear hearing aids) but it would depend on the degree of hearing loss as to wether you could pass a class 1 medical to get a commercial licence. 

Yeah. It's all done by computers and flashing lights these days.

Fair question. I suppose it's possible provided they can demonstrate a dedicated/efficient ability to communicate to ATC and CTAF. 

Maybe not. Because they need to communicate with the control station always.

No.  Pilots have to be able to communicate with air traffic controllers.

Pardon?                                                                               .