firs of all it's great to have a new browser Option here on Windows phone!
thank you and welcome at wp! 
it's also really great that you provide a lot of unique Features that we don't see with Internet Explorer for example.
but there are two big things i'd like to point at which are really not good yet:
first is the design: the design of the opera mini beat app is really not worth looking at (sry). it looks like the old opera mini from Windows mobile or even Symbian S40... but this is Windows Phone! it should look more flat and minimalstic. please have a look on Microsofts design Guidelines or on other apps on Windows phone (i.e. here maps or all of the bing apps like News and weather... of course a browser is sth different than a News app but it should still provide great looking design) . it is possible! i believe in you !
the second thing is probably due to the beat status i hope you'll get that fixed for the official version. it's the rendering of websites. it really does a bad job right now. mobile pages look ugly and old fashioned. often the desktop page is required...
looking forward to seeing updates coming!