[Al Skierkiewicz]

Marley,
Autocad gives you an incredible amount of flexibility to automate certain tasks and to set defaults for just about anything you can do.
For the insertion, you likely have the insert variable set to 0.5 for the insertion scale or the original part was drawn half scale. Just watch the prompts on the screen and see what the default is. If you just hit return, Acad will accept the default.
For dimensioning, you have to set the units within the dimension style dialog. This is where you can change the font of the dimension text, scale factors, arrows and offsets for the dimension lines, etc.