For all your VLAN questions, please have a look at this topic:
http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1
Information on PoE:
https://help.mikrotik.com/docs/spaces/ROS/pages/19136769/PoE-Out
In regards to the roasting:
Untagged VLANs are set on the port (/interface brdige port), you don’t have to set them explicitely on the /interface bridge vlan (might cause conflicts).
Using /interface list member can be usefull when doing firewall (you can use interface list to block/accept). As you don’t do any firewalling, just feel free to remove it.
Last remark, add bridge to tagged vlan 99 as well (for management purposes).