I have had several of the Garmin GPS antennas fail over the last year.
If you get the message, have a look at your 430W satellites page.
If you have no satellites all of a sudden, then your antenna is toast.
It starts intermittently, where all the sats drop off, but are fairly quickly regained...
Yes, 6/32 is the go.
I drilled the mast first, then inserted the pitot tube in and marked it.
Then drill the pitot tube in a drill press.
It's a bit fiddly to get the hole angles correct, but as mentioned above, there is lots of good info around.
I don't know if the grill sensor would work, but the below if from the manual.
It can't hurt to hook it up to the general purpose temp sensor pins and try different configurations.
You didn't mention if it was Skyview or not.
With the OAT probe supplied for the ADAHRS unit, it has the connector not installed, just loose wires with the pins on the end.
Connector goes on after the wires are fed through.
If you are using microfit connectors, can you do the same thing?
I'm pretty sure you can set it up with the labels you want in the 50% page, depending on which widgets you choose.
In the bottom band display I've not seen it, probably due to space limitations, and there would be a confusing amount of numbers.
Get someone to SWR check your antenna from the transceiver end (so coax and antenna together)
If your SWR is way out, it will damage the radio.
Most modern radios have protection built in, I don't know if the 760 does or not.
I know with the older radios, if you transmitted into very high SWR...
I have had one of the little black 3 wire connectors for the backup battery fail before.
By disconnecting/reconnecting and wiggling, I could get the fault to appear and disappear.