Upvote:1
"... I plan to visit my country for three days to do some job interviews"
Ask the interviewers if you can do phone/Skype interviews. These can be followed up with face-to-face interviews later, giving you longer with your family.
Upvote:4
As @GayotFow has recently explained, by policy, the UK allows only a single type of visa at a time, similar to Schengen visa issuance. So, yes, the T4 would become spent when a Standard Visitor Visa is issued.
The wrap-up period is intended to allow students to remain in the UK whilst making their preparations to leave the country. As you were advised, it is risky to leave and attempt to re-enter the UK during this period on the Tier 4 visa, as your reason no longer matches the purpose of the visa (i.e. to study).
Once your Tier 4 leave is cancelled, so will your dependantβs leave be cancelled (unless there are otherwise exceptional circumstances, and staying for the end of the children's school term is generally not such an exception). However, their wrap-up period would be similar to yours.