Do i need a heck & neck mri to rule out any cancerous cause of a lump in throat feeling, bloody saliva, enlarged tonsil/tongue lymph node or just neck ?

Both: If you need to get an imaging study, then yes, you want to include sinuses, salivary glands, as well as neck structures. Ct may be fine, as opposed to mri. Speak to you doc.

Exam: The first step is a clinical history of your symptoms and a physical exam by a health care provider. If it seems appropriate, imaging may be done. However, it may be entirely unnecessary.