1st problem... Get rid of the bubbles, whatever it takes.
You'll never be quite happy with the performance if you don't.
Since this is an initial run-in period, you could also run it too lean and fry it.
If this engine has a remote needle valve, start there. Replace any O-rings on the
needle, make sure the tubing fits TIGHT, or cut pieces of tubing to slip over the
existing tubing at the connections, to ensure tightness. Make sure you have no
pinholes in any of the tank plumbing, but if bubbles are only between the needle
and the engine, and not in the line to the needle, then it's the needle assembly at fault.
(Of course if they're in the entire line, all the way from tank, you'll have to
find a way to insulate it better, or switch tanks if you need to. Bubbles=bad.)


2nd problem...

Either use the EPA (end point adjustment) feature on your radio, if equipped,
or mechanically adjust the throw on the carb. With full UP throttle trim, and full
DOWN throttle, you should have a small opening... enough to let it idle.
It should only shut down with the throttle stick when the trim is ALL the way down.
I noticed this is the initial run-in period... it may take awhile to get a totally reliable
idle anyhow... but it should be able to at least sustain a fast idle if adjusted properly.