Bridge mysteries explained: http://forum.mikrotik.com/t/routeros-bridge-mysteries-explained/147832/1
How to deal with VLANs: http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1
Inter-VLAN routing is just a (not so special) case of routing.
L3HW offload: https://help.mikrotik.com/docs/display/ROS/L3+Hardware+Offloading (I already linked this document). It’s not entirely different than “normal” routing, it’s just a few things have to be set up in a particular way while for “normal routing” it’s possible to do it in a few slightly different ways.