Osc is not very recommended to use on mutual server specifically if if you not access to a console.
Indeed, if you want to create a new theme, you need to know to create a symslink.
Also if you can not customize your apache, php it's worst. You can try with an htaccess but in your case, if i understand well, you have just a simple access. I recommend you to change for another hosting. Your problems will be resolved.
try this, o2switch.fr