there is a house directly south of the MART in Missdeep city, and it has a back door I was wondering if there is any use for this or if it is just there to surprise peoples

That's for the Mini-games in Emerald, and the E-reader in R/S

next question!

Whats the point of the lilycove museum basement, and how do you get the crystal(stone?) statue

The basement is where the paintings of the master rank contest winners are (you can get them painted by first talking to the old man in front of the stairs, and then talk to the artist in th econtest hall)

and you get the glass statue as a reward for winning all the master rank contests

somthing is missing, it diddnt work, does it have to be right after you win?

also, which stairs?

well maybe you talked to the wrong person. the guy is supposed to say something along the lines of, oh we should get some paintings in here, hey would you help us fill this room?, after the guy says that, just win a master contest and the artist will come up to you after you win and say i wish there was a museum to put these in, and then he'll ask you if you know a museum.

After talking to the Curator in the museum (he is the basement), you must win a Master Contest with at least 6 stars and 7 hearts. When you get that score, the artist will say he got inspired by your Pokemon and he will give you the painting, but if you get less points, he won't give you anything.

ah, THERE is the answer im looking for!
unfortunatly my blaziken is maxed out in beauty with a scarf and it still only got 3 hearts
and my milotic isnt ready yet (still need a moveset)