Re: Using a 350 Bridge as an AP to extend the range.
A 350 Bridge can be used as a repeater in the same way an access point can but IMHO the use of a repeater should always be the last option in your network design ( there are some valid reasons to use a repeater). A repeater will half the throughput for all clients that are using the repeater as the repeater has to receive every packet then re transmit that same packet.
As the repeater is retransmitting every packet that it receives it can increase radio congestion and will not help to reduce collisions.
The bridge spacing parameter is used to overcome the range limitation within the 802.11 standards (not to be confused with range limitations caused by RF) and should only be used for BR to BR links as this parameter can not be altered on clients or AP's
The best option for your problem would be to create a "CELL" design, the idea being that you have multiple AP's all on differenet channels each cell (the area that the AP's signal can be received in) will not overlap with another AP that is on a channel that is overlapping.
Typically you use CH 1 6 and 11 then repeat the pattern, to deploy this type of network you MUST do a propper site survey as it relies you the the fact you know where the cell boundries are. You have a small overlap (with non overlapping channels) in your cells to allow for smooth roaming.
The advantage of this design is a much lower client to AP ratio giving you more 'effective bandwidth'
To acheive this you may need to use lower gain anntenna and lower transmit power but these are the things you need to look at in the site survey as every site has its own requirements