Originally Posted by
lizardvalley
Hi everyone! I'm new here, but I've been reading for a while...I think this is probably the most appropriate place to ask my questions/get advice, but if there's a better thread, please let me know

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Wow, you've got my vote for best First-Post! That is a mouthful!
You asked a lot, but I'll address what I can in rapid fashion.
You probably had the regular gold CIBC Aerogold Visa, that's why you were sold into a TD Platinum. If you carried the CIBC black AeroInfinte, then it would have converted to a TD Infinite Aero Visa... btw, the AF of the Platinum Visa is actually $89/yr, not $120.
Yes, correct, you're going to get a new credit pull with any new card application. Unless you can convince them to upgrade your new/existing TD Platinum Visa to the Infinite, which would then bypass the credit pull. If you're really lucky they might even upgrade you with the $0 FYF and 15,000 Aeros, as some people got this a month or two ago.
The National Bank of Canada World MC, I have the
World Elite version of the NBC MC, via a targeted postal mailer sent to me with "By Invitation Only", but others had been able to get it by calling in to enquire (not easy though). It was on promo earlier this year at $0 FYF. Also, it provides up to $250 credit for various aiport fees ($100 parking, $100 baggage fees and $50 airline seat selections). If you go for this card, call and ask if they still have this promo, and for these features. I too like the 60days medical coverage, and you don't need to use it to purchase your travel/flights for this coverage.
The Amex Gold will not count for 2x points on groceries at Costco/Walmart, unless you can call and convince them. Use the GCR $50 cash rebate to apply for this one, for 25,000 MRs and $0FYF.
You said you don't care much for Aeroplan, but the Amex Aeroplan Plus Gold is the only really good option as a $0 FYF card with 30,000 Aeros using a referral (5,000 less via direct signup, such as $40 cash rebate at GCR).
The Chase Amazon.ca Visa is a no-fee and no forex fee card, so it's a keeper. Be careful with using this for rental cars out-of-country, as I don't think there is any insurance coverage. I would avoid if that is the case, I just don't recall right now but can check on it later.
Credit scores, for the most part, are less affected by applying for CHARGE cards (the Amex Rewards and Aeroplan Plus are CHARGE cards). Visa and Master generally will result in bigger drops in your score, but it's really on a per person basis, so YMMV.