Moving to England

No welfare of any kind unless holding a passport from some EU countries. You need skills to work in the UK as there is a skills shortage. Its expensive to live on a day to day basis, and like many other countries in the world, you need to either be sent overseas to a specific job or have the right to work in the UK. Your heritage plays no part whatsoever in being able to get a job, but it could be a reason to do some sightseeing to find your roots.

Yikes.  A lot of questions.  If your parents were English I think you would be ok.  Not so sure about Grandparents.  Claiming benefits is difficult if you have just arrived.  Basically, if you are from the EU, you have to have been in the UK for 3 months.  Also, there is something called The Habitual Residency Test-which is basically what I alluded to.  This is taken very seriously and evidence is needed to show how long you have been in the UK.  In terms of benefits, you could apply for JSA -Job Seekers Allowance or Income Support or Employment Support Allowance or even Council Tax Benefit and Housing Benefit to help with your rent.  But this is not going to be possible if your visa is stamped with 'No Recourse to Public Funds' and you have recently arrived.  Another idea...I believe that Canada is part of the Commonwealth-this might be an easy way to approach this.  It is difficult mate, not trying to put you off but just informing you.  One last thing.....Good luck.

London especially is wildly expensive. It's gentrifying like mad, and both rents and house prices have gone insane. The good news is that--at least as I understand it--if you're accepted here as a resident, you're covered by the National Health Service.