Short Term Stay and Expenses

What do you need the internet for?
Reading forums and sending emails is very different to watching or uploading to Youtube, thus might well produce different answers.

SIM card - The best coverage is normally using Telkomsel. Not the cheapest but often the best. Don't buy the card at the airport because they charge silly money.

A shop is the best - You'll need your passport to buy one

Grapari Telkomsel - Mall Bali Galeria
Simpang Dewa Ruci,, Jalan By Pass Ngurah Rai, Kuta, Badung, Kabupaten Badung, Bali 80361
https://maps.app.goo.gl/jQUC7JButfJdntyi7

If large file uploading is required, there are plenty of free hotspots around, this example in Kuta being one of many

Telkom Wifi.id Corner Tuban
Jl. Raya Kuta No.104A, Kuta, Kabupaten Badung, Bali 80361
https://maps.app.goo.gl/swzNd5AsuVgRgfis9

Over 30 days.

Ask at the airport about a paid 30 day tourist visa, these being extendable for a further 30 at immigration.  I believe the process takes a few days but I've never done it so that needs checking.

Lots of people drive without a valid license but this can be a problem, partially because it leaves you open to fines, but a crash can leave you between  major problems, often expensive, and massive trouble. That could include your own medical bills as your insurance company may refuse to pay out if you were engaged in illegal activity that caused injury.
In the event of a crash, you'd probably get stung for repairs to both vehicles and everyone's medical bills. If there was a fatal crash, it's bills and probably prison.

A local SIM C is available for tourists and I understand international permits are accepted with restrictions but I can't give you details as I have no experience as a tourist using either.

1. No idea.

2. I don't know any supermarkets in Canggu. There are a couple in Seminyak, I usually go to Bintang Supermarket.

3. No idea, but easy to find out about them on the internet.

4. Sure, USB sticks are available. Personally I don't use them because so many places offer free WiFi.

5. Nope.

6. Either apply for a 60 day tourist visa back in Toronto, or pay IDR500k for the VOA once you arrived and then pay a second IDR500k at immigration a couple of weeks later. Doing it in Toronto should be better so no time wasting at immigration in Indonesia.

7. IDP will always be accepted even though the official rules on this are a little complicated.

8. Get travel insurance either in your own country. Indonesian medical insurance is expensive.

All above answers I can’t argue with, and very similar to Phuket answers accept WiFi is free every place you go and tends to be super fast as the norm most homes in Thailand run on 50+mbps absolute minimum for about us$ 12 per month SIM card package even for international calls are Cheap
Thai baht is on a high at the moment can’t say how this is compared to Canadian $ historically
But IDR is pretty normal ish/ running on an average so to speak so against most currency (I work on sg$, us$, gb£ etc) spending will go further in Bali, I worked for a while in Thailand and hold a local account so my spending that way is considerably cheaper than 90% of other people
You will have similar requirements as Indonesia for your visa and similar ways to extend
But 1 month in the same place would kill me Phuket and Bali have airliners that can take you in country to many places and international but we are all different
Safety, Phuket is like many places Bali is no exception you’ll get many proposals for encounters with same/ opposite sex for a price but more in your face in Thailand
Possibly see a little more trouble in Thailand but again similar
Drug issue similar
Taxi scams in Thailand are world famous
Road safety/ crazy drivers similar but enforced more in Thailand
Driving License I can’t remember as mine has expired and rules have changed in Thailand
Health insurance I would get for Thailand but in my opinion medical care is better in Thailand, that said my experience apart from one has been very good in Indonesia, medical costs are slightly cheaper in Indonesia 
If me I would do both if not a 3rd and 4th country loads of stunning islands in that part of Thailand and good time of year to go and then venture around Indonesia

I agree with the adivice above, just two clarifications:
no more possible to get a tourist driving licence in Indonesia, u must have an international one from the motorization office in ur country, please note that Indonesia adheres both traty, Geneve and Vienna.
U can buy food to the local markets in Canggu, but there are also supermarket with import food like Canggu Deli or Pepito (of course more expensive than local market).