1. Yes.
You can even have both of these in same context
2.ACE context can bridges between multiple client/server pairs.e.g.
Traffic from vlan10 to vlan20 is bridged
Traffic from vlan30 to vlan40 is bridged
3. from load balancing perspective you can achieve all functionalities in both modes.
In bridge mode all broadcasts/multicast passes through the ACE.Bridge mode has some Nat limitations for non-loadbalance-traffic.
Hope it helps
Syed Iftekhar Ahmed