It sucks for the TBM as well... 
Bomber icon for formations only would make chosing a single bomber (which includes the C-47) more viable, and thereforr AH more tactically diverse. 
YES! +1
With my mossie XVI I could fly into a contested base and defenders would scoot out of my way thinking that I am a Mossie VI and that they are about to eat a faceful of hizzukas. Not any more.
If the radar is up the scam is exposed immediately and I attract every fighter in the sector. At least with the mossie I can still slip through, lob my bomb and try to bolt out of there, but if I am in SBD - forget about it.
In those cases they wouldn't. But they'd certainly know a single Lanc, B- bomber, or A-20 from a pony/spit/Ki/yak/F-series plane.
No. They will not.
But I spent only a few year staring at radar screens and you express such certainty that I have doubts.