Hi,
1. Make my title block look and work properly;
Generally in Revit, controlling line weights consists of three parts.
Part 1.
Revit has 16 different possible values for lineweight, which are controlled through Manage>Additional Settings>Line Weights
This should be set up in your template and really shouldn't be changed - see this document (page 22) for a decent setup.
Part 2.
The second part is line styles, which are controlled in Manage>Additional Settings>Line Styles
This controlls availible styles for detail and model lines in a project (to add a new style you need to click on Modify Subcategories>New)
Part 3.
All objects have a default line styles associated in a teplate- go to Manage>object Styles to modify to add or modify a line style (this also works in family environment, again to add a new style click on Modify Subcategories>New) If you create a new style in a family it's added to a project with the same settings as in the family.
As a good practice is better to keep the number of line styles to a minimum and spend some time to set up the the object styles correctly, so they look the way you like it (or as per your office standard).
2. Change the way light fittings appear in plan.
As for the lines, that's really the same thing as above.
To add a filled region to a lighting fixture family, you'll need to create a detail item family, draw the filled region and load it into the fixture family.
Hope this helps,
Maciej
