Why do I feel that rainbow dash is a better friend than the people I hang out with?
Hehe that's a funny way of putting it. But if you really mean it then maybe you don't hang around the right people who treat you well. Try meet someone new who could treat you better the the previous.
Technically, she is not. Surprisingly it is Fluttershy. The Hub recently had a marathon of My Little Pony episodes revolving around the "fan favorite" pony. They asked viewers of the show to go online and vote for their favorite pony. Fluttershy won the fan favorite vote. But, I think a lot of people like Rainbow Dash because she "Is about 20% cooler" (Quote by Rainbow Dash) than the other ponies.
Rainbow dash is a girl. All girl ponies in My Little Pony: Friendship is Magic have eyelashes and rounded muzzle, Rainbow Dash has both. She is addressed as a girl in the dialogue from Sonic Rainboom: "Rainbow here really is the best flyer in Equestria!" - Rarity "I know SHE is my dear!" - Princess Celestia
Most likely Sonic is faster. Sonic can break the sound barrier without much difficulty, if the TV series' are to be trusted. Rainbow Dash, on the other hand, has only done so twice and only with strong motivation. Rainbow Dash is faster unless Sonic can surpass mach 10 Rainbow Dash can go fast enough to shatter the light spectrum
The names of the My Little Pony: Friendship is Magic characters remain the same internationally. Therefore, in the Spanish edition of My Little Pony: Friendship is Magic, Rainbow Dash's name is still spelled "Rainbow Dash". This information was found on Hasbro's International website. However, the phrase "rainbow dash" literally translated into Spanish is "arco iris guión"