I just checked my 2s 2400mah 7.4v transmitter lipo and it had an IR of 74.5 on one cell and 71 on the other. This seem quite high and the battery is less than a year old. The battery did not swell, is it ok to use?

The current draw is so low for a transmitter, that high IR will not affect anything. I'd use them as long as they hold a charge for a while.

A lot of the IR comes from bad connections, at least for high current draw.

I made a radio battery out of an old race pack, and with a balance connector on and plugged into my Icharger it measures lower IR than without the balance plug.

Still though the low power of a radio high IR doesn't matter

Agreed, IR is not important for Tx packs, I would check the capacitance instead, though I would discard the pack if any signs of swelling are present and probably not a bad idea to replace a pack that's over a couple years old, but not necessary provided the pack holds enough charge to suit your needs.

Do you guys pull the pack from the radio and storage charge it? Lipo seems more of a pain for a transmitter.

How else do you want to do a balanced charge?

I was very happy that my transmitter was LiFe compatible. I just charge it when it's low and that's it.

I drilled a hole on the side of my battery tray to feed the balance wires through and use this portable USB charger plugged into the back of my iCharger, no need to remove the battery from Tx this way:

That IR seems normal for a TX pack. The IR measuring process doesn't just measure the cells, it also measures the wiring. TX packs have pretty small wiring.