Thanks for your answer. At this stage, if I would rate it 'Good Service'. I want to give you an 'Excellent', so I'll be seeking further information if applicable.
On what grounds does my residence card supersede my student visa? It doesn't seem like this scenario is addressed on the UKBA website. As far as I know, one of the grounds for refusing application for Indefinite Leave after the 5 years route is if an applicant has broken any immigration rules. So, would working over 20 hours not mean breaking an immigration rule at some point? While I get your answer that a residence card supersedes a student visa, I just want to be clear on what grounds to make that conclusion. Thanks a lot.