Installing SQL Server with Virtual Account / (managed local accounts) I am installing SQL Server 2016 by using virtual accounts (which I suppose is managed local accounts) and I cannot see any limitation, drawback of using this simpler method vs. using MSAs. 

Would a more experience DBA educate us? 

My understanding is that: as long as you do not have any cross-server operations, you are fine. I will not cross servers, but I will cross SQL SERVER INSTANCES (on the same server). Are there any issues that I may face?

I've read these resources and another similar question.
Based on your description, I don't think you'll have any issues with either account type. One important consideration is whether you have any internal/corporate or external compliance requirements with regards to the service account used by databases. 

Depending on the actual policy or compliance requirement, you might find explicit wordings about password management which doesn't exist with VAs. Real security impact is almost never the issue as most of these policies (that I've worked with anyway) are either really dated or written by a "general IT professional" or both. Trying to convince whoever manages these policies or the auditors has never worked for me. Just educating them on how VAs work can be an exercise in futility.

If you aren't affected by such policies/requirements and are unlikely to be in the foreseeable future then you'll be fine with VAs. Else, you're pretty much pushed down the path of MSA or some other form of human/tool managed account.