Personally, I view appending the name at the end of the title to be more for branding than for SEO. If you are trying to build a brand, it can be very useful to reinforce it by placing it at the end of all of your title tags. This works great if you have a unique brand and your brand name is short enough to actually fit within the character limitation of the title tag while still giving you room to describe what's on the page.
Regarding whether or not to use ".com" - I think it depends on your business and your intent with the site. If the majority of your business is taking place online, then the .com might be very appropriate. Or, if whatever action you are hoping the visitor takes is an online action, then again, the .com would be very appropriate. If, on the other hand, you are a plumber and what you really want is for them to call you, then maybe leave the ".com" off...for example "Roto-Rooter"....if you search "roto-rooter Seattle" you'll see they append "Roto-Rooter Plumbing" at the end of their title tag, not "Roto-Rooter.com"
Hope that helps!