Owning 5% of a company, good or bad?

I'm just a trader, not an investor but I accumulate some stocks I like if the price keeps going lower and hold it until it pays well enough. So in that sense I'm an investor sometimes. I just realized I accumulated so much of one company that looking at my shares and the outstanding shares of the company, I now own over 4% of the company. I'm wondering, what if I buy a bit more and own 5% of the company? Will they send me mail or otherwise be in contact with me, and will I get voting rights or any other privileges? Is owning too much of a company a bad thing? Will the company or market makers know I own so much stock and make the price go lower until I sell my shares? Any expertise on this matter is appreciated!