I would call MS directly to make sure you know what you're purchasing. I'm not completely up on 2012, but from what I've seen (and being that it is the "replacement" for SBS), you are only allowed 2 RDP connections to Essentials, for administration. You cannot install RDS on Essentials (same as SBS was).
You are limited to the number of end users (same as SBS), which could become a problem in the future.
And it is also my understanding the Hyper-V role is not there for Essentials, so you cannot use Essentials to run virtuals.
Also, if Essentials is the same as SBS was, it will force you (there were ways around the old SBS, not sure on Essentials) to install as an Active Directory/Domain controller environment. Running RDS on a domain controller is not recommended. And honestly, for what you're looking to do, having something that is a DC is only going to add to the overhead.