(1) There is no Oneworld or AA partner with direct ANC-YVR service; AC is the only airline that flies that route, seasonally.

(2) You can use AA miles to redeem on AS, ANC-xSEA-YVR. If you want to stop over in YVR, then it will likely be two separate one-way awards, ANC-xSEA-YVR, 25K AA miles for F (Y on SEA-YVR) then another 32.5K AA miles for CX F, YVR-JFK, or 25K one way YVR-JFK in J. If you don't want to stop over, you ought to get away for just the 32.5K F award.

(3) I'd just phone AA with your dates, ideally a range, to ask about availability. If you use KVS you can look for space, or if you use EF you can see AS space (AA typically has the same inventory) but not CX. Phoning will be easier; you'll have to phone to book anyway.

(4) There is no ferry ANC-YVR; the AK state ferry runs from Whittier, south of Anchorage, to Juneau, then connects to a second ferry that runs to Bellingham, WA, around 60 miles south of Vancouver. The ferry from Whittier to Juneau runs monthly in the summer and takes 2 days; the ferry from Juneau to Bellingham runs weekly and takes 3 days. There's usually a 2-4 day layover required in JNU, thus it takes around 7-9 days all in. You can take a bus or a train from Bellingham (or indeed, Seattle) to Vancouver. Flying is much cheaper, as is (typically) a one-way cruise ship in the summer.