You can buy a monthly pass from a retailer to save waiting for it in the mail:
https://www.edmonton.ca/ets/where-to-buy-fares-passes
#2 and #3 sums it up, and it is an easy way to take transit if you know for sure you'll be taking a lot of transit.
But you should really go Arc Card. Benefits:
1. It still has a "monthly pass" but rather than paying for it up front, you pay for it as you go. Once you reach $100 in a month, it no longer takes money from your card.
2. You do have to tap in and should tap out any time you take the train and bus. Tapping out is not necessary unless you're taking a suburban bus that has the possibility for a higher fare unless you tap out.
3. If you lose your card, you can call customer service and have the balance transferred to a new card.
4. You can start using it right away for partial months. It's $2.75 to use your Arc Card vs. $3.50 for cash and $2.775 to use one of 10 pack ticket.