[the18thtee]

What do you mean by "refuse to resume"? Do you get an error message or does it try to connect then fail? Details...
And if you are on Verizon, why are you using/trying Sprint roms/radios/anything?
If im not mistaken, when the arrows disappear, that means there is no connection, not that it has idled. The idle indication is greyed arrows.
These issues you are having sound (to me) like a problem created by switching between different carrier roms/radios/anything.
A good way to make sure that you have all the right settings for VZW is to flash back to the Stock ROM, hard-reset, and go through all of the reactivation procedures (*228, etc.) and then upgrade to the 1.0.4. kitchen with the built in carrier customizations, hard-reset, then soft reset when the "customizing in 3 seconds" box pops up (or just flash the blank extrom).
It is never a good idea to use upgrades that are for other carriers.

As for the phone freezing problem, I have heard that voice command can cause problems like this, or any other software installed that works with the phone program. Do you have anything like this installed?
The inability to call out, once again, sounds like it is related to the different carrier software you have switched between.

In any case, it is probably a good idea to flash back to stock then reupgrade.