Hi Demxy,
I wouldn't say it is dangerous, as long as you are consuming plenty of calories and water, and you don't allow yourself to feel too tired.
I was losing around 14 pounds a month for about 3 months or so last year [was 322 lbs, 6'3" tall].
Building up muscle is great for burning calories faster - the extra muscle may mean you don't lose weight as fast, as muscle is heavier than fat, but which would you rather have?
Also more muscle means higher metabolism, so you will burn the calories off much faster when you do cardiovascular exercise such as walking/running on your treadmill.
Hope this info helps, Mike.