It will take 5 to 15 seconds per tap for transaction to go through, slowing down boarding and station entry.
Absolutely unnecessary; it's not a $50 purchase (nor does it take 5 seconds in most retail outlets). TTC can take a bit of risk that of a small %age of trips might be made for free (they already do; it's fare fraud).
Accept by default doing local checks on expiry date and the like (transaction time below 0.1s) and process in a central location after the fact (a split second later during typical operation).
If the card fails, publish that to all machines immediately; the rider will not be able to transfer (most trips require a transfer or are bidirectional) and that card is now blocked. If we require an exit tap, the user will not be able to leave the station with that card either (install fare payment device inside fare-paid area at all stations). 1GB storage per device ($5) can block hundreds of millions of cards.
What about discounts for frequent users?
If card is valid, put a $20 hold on the card (fallback to cash fare if $20 fails). At the end of the week (or when they hit $20 in riding) charge the card for full balance owing; pay bank for that single transaction. First trip is cash fare, all other trips might be token fare.
Allow user to close their account manually (charge card + release hold) via a fare payment machine. Perhaps they can change their permanent preference for that card number there too.
What about kids? Parents don't want to deposit money into a kids bank-account so they can ride transit.
Register a card in advance (perhaps are a fare machine) as identification only. Point that identification card number at a separate payment account such as a parents credit card. Child can now use whatever NFC enabled card they have, including their phone or a TTC issued card, as identification and the payment is charged elsewhere. ID only NFC is really cheap to implement; at a few pennies per card (many agencies use disposable ones for transfers).
Yes, accept by default will cause TTC to eat a few fares this way. It's going to be pretty rare; they've certainly eaten their share of Presto fares when all machines were unavailable.
Need to pay credit card companies to collect information on customer travel pattern.
Also completely unnecessary. You think Walmart doesn't know which checkout-lane you made a purchase at because you tapped Visa at the till?
Yes, those hand-held devices that small retail uses (because they don't want to roll their own transaction processing backend) tend not to give much feedback but TTC has millions of transactions per day; they can (and did: see Presto) roll their own transaction processing backend which collects information they want.
Some customers might rotate cards to reduce TTC from tracking them (losing frequent rider points too). Of course, we have people on this forum with 2 or 3 Presto cards. Ultimately, TTC wants to know about about broader network use patterns (are those 500 9am walk-ins at Kennedy station exiting at Dundas station or Eglinton Station?) than whether an individual named Fred consistently begins their weekday commute at 8:10am at St. Clair West.
The real issue is we keep going back to Accenture for our software tech solutions without much of a plan in mind beyond "this seems nifty".