Hello,

i'm interested if there is a possibility of balancing the L2 pipes with OSPF?
As visible on the picture i have two sites, both site has L2 Pipe to my BGP router, however my internal net is OSPF.

With OSPF, backup is already configure, so if Site2's L2 link dropped, every traffic re-routed via Site1's L2 link.
I have some servers in a specific subnet at site1, all other things are in (or mostly thru) site2, so i'm interested if there is possible somehow to

1) some prefix of Site1 directly over it's L2
some other prefixes of Site1 over Site2's L2

2) access network to any prefix of site via Site2 than Site1?

This would be very difficult with OSPF and would most likely involve policy routing. BGP is really what you want to use to move subnets around via policy. You can still use BGP in conjunction with OSPF. Here is a presentation we did at the USA MUM in 2013 on using BGP as your IGP.

Take a look at local preference in BGP...it works well for the scenario you described.

http://mum.mikrotik.com/presentations/US13/kevin.pdf