Alright interesting so I assume then that when shit hits the fan in 1734, that Frederick the great and not his mother would inherit the throne?
There's also the chance that they make his father king, of course I somewhat doubt that, mostly because of Frederick Williams personality.
That'll have interesting consequences should the jacboite rebellion of 1745 still occur.
It really depend on how long the War of Austrian Succession last. I lean toward beside Prussia, Saxony will likely also side with the Habsburgs (mostly because they now lies between Austria and mega Prussia). Denmark may also join, now that they have a stronger position in Germany, if they join they will fight on the British side. The Swedes may repeat OTL stupidity by attacking Russia, through they may get a rare moment of sanity because the Russians and Danes are on the same side (so Sweden may decide not to enter the war if Denmark have joined the pro-Habsburg side). So the question are whether the anti-Habsburgs will last until 1745.
Some long term effects:
Sweden stay neutral: They keep a better border in Finland, smaller chance of losing it later, con: the Cap morons stay a power factor in Sweden. So they may start a war with Sweden later. But with a little luck they're couped by the next Swedish king before that happens.
The Danes enter the War: Likely no territorial gains, if Denmark gain something it will be because Denmark and Prussia partition Münster (unlikely the bishop was a good political opportunist, changing sides as the wind blew), so Denmark will likely only get a lot of money from UK, they will likely be thrown into minor colonial projects and modernisation.
Prussia: will only gain something, if the Bishop of Cologne-Münster etc fuck up. In that case Prussia take most of his possession with Denmark and Hesse-Kassel taking minor parts.
Saxony likely gain little except for some relative gaining important Bishop titles.
Bavaria risk partition, if their alliance do badly enough.
Also re Frederick having issue could we see him perhaps marryong Amelia of England before her family dies? Potentially having issue and then dividing the nation's?
I don't think he will have issues. His brother or nephew will likely inherit all of his possessions. This will be interesting, as it may means that they may live in Germany only travelling to UK, when it becomes clear that Frederick won't produce a heir, which means Frederick will be followed by a heir which is as German as he.