Switching employer soon after joining - risky?

I've been offered a job under Tier 2 (General). I just received my passport back yesterday with the visa vignette. They haven't sent me an official offer letter (with start date, salary, etc) but we agreed on a start date and salary over email. I don't know what the notice period will be.

However, during this time, a different employer has indicated interest in hiring me, and are offering at least 30% higher salary.

Due to already having a visa, and not wanting to add any complication or risk losing the visa I already have, I decided not to take the other offer yet. Instead, I asked them to wait until I get settled in the UK first, and then if they still want to offer me, then I can switch the visa over to them.

If I was to switch employer, I would make sure it was all within the terms of the original employer's contract. For example, I'd provide the appropriate notice (after I'd received a formal offer) and I'd do the full amount of work required up to the leaving date.

However, I'm still concerned about whether leaving this employer so soon after joining them would cause issues for me down the track.

A) Might doing this make my 'extension' application look less credible?
B) Might the original employer, if they were angry, be able to lodge some kind of complaint to the UK government and have me removed or my visa cancelled?
C) Might this somehow damage the credibility of future visa applications, in the UK or even elsewhere?

Any thoughts about this?

Thanks for reading!

A) Might doing this make my 'extension' application look less credible?
B) Might the original employer, if they were angry, be able to lodge some kind of complaint to the UK government and have me removed or my visa cancelled?
C) Might this somehow damage the credibility of future visa applications, in the UK or even elsewhere?

No, no and no.