We have an existing Wifi network design with Hub-spoke Model with PoE Switch as Hub, and EAP225 as spoke and a cat6 cable conecting the hub and spoke. 

But now, we are try to cover a building with Wifi where cabling looks unfeasible. Their are cat6 cables laid by the property developer, but 80% are damaged and repairing/replacing them does not look feasible as they are laid in conduits inside brick walls and large number of 90 degree bends (electrical cabling contractor did not probably understand the difference in eernet cabling and AC cabling). Effectively not there. We maybe able to some repair jobs by putting pressure on the builder,  and get the ratio of working cables to about 50%, but not more. 

So current design thought was if we can extend coverage in this building by

(1) Using more capable AP (from the specs) like EAP245 (more users, extra ethernet Bridge port). To the bridge port, we connect a downsteam EAP245/225

(2) Using Mesh to augment the spoke. That mean spoke AP now become Mesh root AP and we have 1-2 further levels of mesh links. We can manage power supply at all places.

My questions therefore:

(a) Are (1) and (2) right way of attempting to resolve this issue ? Any other solution ?

(b) For (1) How many downstream APs we can chain ? Our switches powering first AP will support 802.3at.

(c) For (2), what is the expected impact on client performance and capacity (simulatneous users) when MESH is enabled for both EAP225 & EAP245 ? As mesh AP will use wifi for backhaul, the chipset will have to work extra for this backhaul and their should be some impact. 

(d) Are their any plans for an EAP model supporting 802.11ax in 3-6 months ? Our thinking is EAP 802.11ax gear will have stronger chipset & memory, should give more backhaul throughput and possibly even support more users (which is our need in this building)