Looking for guidance planning the replacement of SBS 2011

Hi,

I am looking for some help with planning the replacement of SBS 2011.  I see a few threads on the topic already, but they seem to cover a transition to Essentials.

I'm already looking at 30 users with potential to grow, so I think we have already outgrown the 'small business' part of SBS.  

I won't pretend to know much of anything about licensing/server features/etc., and don't stay current with M$ release 'news', so starting from scratch would be an accurate statement.

That said, I need to make sure I can replace/replicate the current functions of 2011.  

No doubt this list is far from complete, but these are the things I know it does that I'm worried about replacing (assuming DC/AD roles are covered no matter what route I go)...

• On-site Exchange server

• OWA features for rdp

• Backups

• File storage

• Everything else I don't have the foresight to realize I'm losing

We don't use SP and don't have an intranet...so two things off the list of worries.

I know O365 is an option to replace the on-site exchange server, but I have my concerns about going cloud...namely cost effectiveness, security, and data retention.  I also don't know if it's a seamless transition in terms of features available to Outlook users.

As for the OWA side, we have a few users that remote in frequently from home.  I'm not really sure what route to go on an Enterprise level.  Is a quick and dirty fix just to assign static IP's and route RDP requests via port forwarding?  Similar to the M$ Server line, I'm not too well versed on the latest and greatest options for remote options that are easy on my less than expert user bsaed.

Does the current M$ server line include any sort of native backup feature, or am I on my own for finding a new solution?
 
Lastly, are there any glaring omissions from my early brain-storm here?  I inherited this server and this will be my first implementation/migration...needless to say anxiety levels are high.  If anyone has gone through a similar move, I would love to hear about it.

Thank you for reading.