Forget youtube download using playstore.. as this akif's google apps exploit got busted by tm.. therefore, they won't allow for the google sign in, or google account, which needed for you to install the playstore.. now i will suggest that you do a factory reset to remove that buggy update, but before that make sure you copy out all info (hypptv username, password, etc) before you do factory reset..

my advice, go thru this thread slowly, and u can find in my previous post as well..

just need to install these 2 updates, which u can also find in this thread :

1. Install the hyppapk installer (which will enable the stb to install outsource/non-market app)
2. Install the aptoide (your replacement for Google Playstore)

As for the youtube, no choice but you have to use yotube alternative.. such as youtube for tv (available in aptoide), or other app such as viral popup

good luck!!!

Unless you know how to remove that GAPPS exploit using command line, which unfortunately I don't know how to.. hahahaha..