Git and website development workflow

Many questions have been posted on this subject and I've been reading through them extensively for the past couple days. My concern is specific.

Here's what I was doing before git:

• I run a PHP/MYSQL website
• I develop locally and test on WAMP
• I FTP to a staging site dev.mywebsite.com
• Once I'm happy with all the changes, I FTP to the live site

When I decided to start using Git:

• I initialized a bare repo on my hosting server
• Created a post-receive hook to deploy to dev.mywebsite.com
• I cloned the dev.mywebsite.com repo to a my local dev machine
• I test code -> commit -> push to remote (dev site)

Here are my questions:

1) There are a few files that I need them to remain different on local vs remote (these are mainly config files). I am using --assume-unchanged for these files. However, I read that doing 'git reset' would undo these so my first question: - Is there a better way to never change the config files when I push from local to remote?

2) My workflow ends with me pushing to the dev site. I am not sure how to proceed from there, and deploy my code to the live website in the most efficient and risk free way.

*3) A bonus question: Should I integrate github/bitbucket/etc.. into my workflow?

Thank you