I know using a zone director for my two zoneflex 7982 APs will get me smartmesh support which is super and great, but can I avoid the expense without causing AP contention issues for clients in the small area served by both APs? I don't feel like just two access points should need a heavy duty management solution to effectively cover both ends of our building floor.
With regards to your question, Yes you can use same SSID and encryption on all Standalone AP's without ZoneDirector. But roaming depends on what is your requirement. Let us first see what happens when APs are in 1,6,11 channel.
Setup is such that AP1 (in ch 1), AP2 (in ch 6) and AP3 (in ch 11). Also the AP are in overlapping non-interference mode for perfect roaming of clients from AP1 to AP2 to AP3. As it is known Client and AP association is based on the ESSID-BSSID concept. AP1, AP2, AP3 can be configured for same ESSID, but since there are working on different channels each AP generates different BSSIDs.
So when a client is connected to AP1 it is associated to ESSID-BSSID1. Now when it roams to AP2 ESSID is same but BSSID is different (say BSSID2). So the client has to deauth or diassociate itself from OLD BSSID1 and make it associate to new BSSID2.
Now the trick here is, only the BSSID got changed which is used at MAC (L2) level. It is equivalent to wired client had GATEWAY1 before and now changed to GATEWAY2. So still at L3 level the client maintains the same IP (provided all APs are in same VLAN).
The point is when the client roams from AP1 to AP2 to AP3, only at L2 level client disconnects and reconnects, but it still maintain L3 connectivity (TCP/UDP/ICMP/DHCP) when roaming. That is if a ping was enabled when roaming the ping will still go on perfectly. If a file transfer (FTP/TFTP) was going on, after roaming also it will be maintained.
Having said that there might me a small time (in ms) where the service gets interrupted during roaming. But it is not an visible issue.