problem with separate index.php in public_html

hi there

there is a suggestion here ( to move index.php in public_html folder to ready for upload, by this i have 2 Qs:

1- why when i do the above instructions, the bootstrap did’nt load completely, for example icons in gridview didnt load

2- is it dangerous to put index.php next to backend, frontend, … folders?

thanks in advanced