Is it possible to perform DNS SRV query at node level so that traffic will directed on same.

A traffic type profile indicates to BIG-IP how to handle traffic in the forwarding path. Since your VS will not be receiving DNS traffic for forwarding, it is not necessary to add the dns profile to it. You would need to use a sideband connection from an iRule attached to the existing VS. However, as I say, if you do this, you won't have DNS iRule commands available, so you'll have to manually construct your request (e.g., using

binary format

binary scan

I strongly recommend that you consider engaging F5 Professional Services, a consulting arm of F5. No matter how you approach this, it's going to require a fair amount of work and will be somewhat complex.

Having said that, iCall allows you to execute a Tcl script periodically. It is also documented on DevCentral.