Let's see if we can help out with those questions
Okay, so for number 1 - You can host a .ca domain as part of your hosting package. You will need to set up the NameServer entries on your domain to direct it to the Lunar Pages NameServers issued to you when your hosting account is set up. These details are e-mailed out to you. Details on how to set up the NameServer entry for your domain should be found on your registrar's website. If you are having any difficulty, let us know (here on the forum) who you registered the domain with and we'll try to help out.
You won't need to transfer the domain name to LunarPages.
Number 2 - You won't be limited to a number of pages or size of page on the Basic package. But obviously, regarding size of pages, you won't want to have pages that are so big as to make viewing them a laboured exercise for the visitor. That is not overly likely to be an issue with blog sites, but you'll want to keep an eye on how long they are taking for your visitors to load them. The larger and slower they are, the more quickly your visitors will give up and go else where.
An example of this can be demonstrated by looking at Google some years back. Their website takes about 0.4 of a second to load on average. When they made a small change and it started taking 0.7 of a second to load, they lost 25% of their revenue from advertising. You won't have to worry about keeping your pages quite that quick, but the point at which it is taking more than 2 or 3 seconds to load is the point at which you will start losing visitors.
With regards the storage of files on your account. I'm going to put up section 12 of the Acceptable Use Policy. This basically says that you're free to use the storage space, providing it is for files that are relevant for your website.
You agree not to run a banner exchange, free adult tgp (thumbnail gallery post) and/or free adult image galleries on your website. You understand and agree that shared server space is for business and personal website operations purposes only and not for unrelated data storage.
Number 3 - Unless you have a dedicated server solution, the web server you are placed on will already host other websites. Whilst the number of websites hosted by a server (and their popularity) effect how quickly the server delivers the websites, Lunar Pages load balances their servers. This should not prove to be an issue.
All the best with your venture into hosting a website, and let us know if you have any other questions.