Q: Can "as well as" be used without commas before and after the phrase and does it require a singular or plural verb?

The phrase "as well as" means in "addition to" or "and also" in the context of the example that you have mentioned. When "as well as" is used as a conjunction (i.e. in place of “and”), there is no need to use commas before or after the phrase. Moreover, it should always be used with a singular verb.

Therefore, in your example, the correct way of writing is "John as well as Raju is involved in this project." 

Related reading:

• Quick tips on using commas, brackets, and dashes in a research paper
• 6 Actionable tips to improve academic writing