I will try to answer your questions:

01.will the connector support ?

Yes... RP-TNC connectors are required on the antenna. Thoses antennas contain those ends.

02.is 5.8 Ghz allowed in indoor (safety wise/health wise)? which frequency is recommended 2.4 or 5.8 ghz?

Either frequency will work. One thing you need to look at is budget. 5.0ghz will give you more channels and less interference issues than the 2.4ghz, but it will also require more access points since you get better coverage in the lower frequencies.

03.I think if i use wireless n then coverage will be better than wirelesss g (i want to eliminate any dead spot).I think handheld devices now in market mostly wireless g or a?in any case all will work with wireless n access points?.....

Yes.. plus it might give you better coverage due to multipath in warehouse and manufacturing environments.

04.i want to use only one antenna on each access points on 2.4 or 5.4 GHz....with 5.2 DB Omni ....or if its recommended then i will use thre 5.2 db on each access points.please suggest.

In an indoor environment, I would suggest you use all three. This allows you to use diversity to help against multipath issues. You would need 3 antennas on both the 2.4ghz and 5ghz. The 5ghz antennas are different from the 2.4ghz antennas.

05. I want to use wireless n because its backward compatible and more coverage.Also i believe in comming 2 years gradually many handheld devices will be supporting wireless n....what u suggest.plz comment and recommend

If you want to use 802.11n in the furture, then I would suggest you use the 5ghz side and have a wireless site survey done to verify you have 100% coverage in the 5ghz spectrum.