3 htaccess questions please help me

[pal_20007]

hello,

 

i have shared hosting account with godaddy

 

and i want use htaccess file

 

i made the file with 79 line and its about 4kb

 

my questions

 

1- if i use this htaccess, its slow down my website ?

2- because i am in shared hosting, is it better to use htaccess anyway (even if its slow my web) because if i did not use it another one in the same server may use it ?

3- how to set rewriterule to redirect page if (querystring id=1) then redirec to index.php?cars if querystring id=2 then redirect to index.php?mobiles and so ... ?

 

thanks in advanced