Hi, Val. You should probably begin by watching the Fiddler tutorial video and reading the documentation (and/or the Fiddler book) as you will find the answers to your questions there.
1. Yes, you can easily have Fiddler generate traffic using the Composer tab, or by using the "Reissue" commands or by using FiddlerScript.
2. Fiddler has no problem capturing traffic which is targeted to a literal IP address (which you're calling numeric traffic). Fiddler doesn't care whether traffic uses a DNS address or not; it only cares that it gets the traffic. Virtually all HTTP/HTTPS stacks will send their traffic to Fiddler automatically; a few require extra configuration; see http://www.fiddlerbook.com/fiddler/help/hookup.asp
. However, Fiddler does NOT capture non-HTTP traffic (e.g. UDP, or TCP/IP protocols other than HTTP/HTTPS/FTP) so if your scenario requires those you won't be able to use Fiddler for that task. (And WireShark probably won't help you either, as it doesn't modify such traffic).