If your foreign passport has the following:
Name: ABC DEF
Surname:

then your British passport will have the following:
Name: XXX
Surname: ABC DEF

Your leave will remain valid until it expires, unless it is curtailed. Make sure UKVI and your employer have your current address so that the curtailment lette reaches you whenever it is issued.

1, 2, 3: Read FAQs - From Tier 2 (ICT) to Tier 2 (General) / ILR; Q3.
3, 4: No (245GD(b)).

1. This has nothing to do with current CoS but current leave. Your current leave will remain valid until expiry date unless it is either curtailed or a new leave is issued under new sponsorship.
2. Not an immigration query.

Yes.

1. Switch: PBS dependant to Tier 2 migrant
2. As above.
3. Switching to PBS dependent route or extending?
4. Yes, but your sponsor must notify UKVI that your sponsorship has been terminated.

Edit: I always get beaten by CR001!

Read When to extend PBS dependant leave?

No legal advice can be provided on this forum.
People can only answer questions.

You cannot hold more than 10% shares in the (limited) company that sponsors you and you cannot be self-employed under Tier 2.

It is not the same name! Your name is as shown in your identity document (the Indian passport): Name: ABC DEF Surname: Blank. You may think that your name is ABC and surname DEF, but this is not proved unless this is displayed so in your identity document. You may get away with it in AN application ...

FLR = further leave to remain which can be applied for through any leave to remain (LTR) application form, be it FLR(M) of PBS dependant leave or FLR(FP) or FLR(O) or .... The OP wasn't able to confirm whether the wife applied for FLR using the PBS dependant leave to remain form or FLR(M), as he cle...

Please continue with your ILR queries in the existing topic.

The documents available here will always be the current ones.
No need to doubt or question that!

See also Annex B: residence requirements -> 4. Excess absences in the 5(3) year qualifying period

Don't think OP explicitly said that. Once I got ILR in Mar-2013, I had to change the visa category for my wife. Don't know/remember the name of the form she filled in May-2013 so cant say if it was FLR(M) she switched to. Unfortunately, no one asked the OP what the BRP stated as the type of leave. H...

Please keep your settlement visa queries in a single topic.

I believe your wife has found the answers you both were looking for.

Please follow the suggestion given earlier.

Please keep your ILR queries in a single topic.

Call up HMRC to ask how long or search for a tax forum.

Anyone who had taken TOEIC exam in the past, irrespective of whether the result was used in an immigration application or not, may also be asked to attend an interview.

HCI doesn't process OCI applications, Ministry of Overseas Indian Affairs does.
Once received from MOIA, HCI only stamps the OCI booklet and passes it on to VFS for onward delivery.

Be patient.

It is between you and your employer to decide which SoC your new role fits in more appropriately, and convince UKVI if they have any questions at a later date.

+1. Generics always help and are more useful. e.g. - Queries - Tier 1 (General) applying for ILR ILR after 6 years on discretionary leave The moment I see such titles, I know I am more competent to answer queries in topic 1 and that I best leave topic 2 unless there is a generic query that I may be ...