"Please do not listen to the mortgage advisor. Sorry but not up to date on current mortgages ..."
don't you think a mortgage advisor might be? Effectively you are saying, hey, i know nothing, but listen to me, rather than a professional that does it for a living!
Anyway otto, what about trying a different advisor? If they are all saying the same, then listen to them. You can have more than one mortgage, but it will depend on your actual income and circumstances. And yes, captial gains tax is payable (when you sell) on a home that is not your main residence