Even if a packet was send via a TCP socket you can still send it with UDP, and vice-versa. The only limitation being that obviously you cannot send a packet on an open socket with a differant protocol than the open socket supports.
You can switch the selected protcol for sending under the "Protocol" menu:
Packet Edit Studio also has the ability to send packets on a loop timer.
Under the "LoopControl" group check "Send on Timer":
Next to it you can control the wait period between send calls:
You can start a send loop the same way you would send just one packet: by pressing the "play" button. To end a send loop you can press the stop button. You will also notice that the play button turns into a pause button while sending. This allows you to temporarily suspend sending.