1. Yes
2. GetBreakpoint is the old not added by me, GetStackFrame is added by me I think. Probably they should be made to match
3. return 0 in GetThreadsCount() and GetThread won't be called, you can return return cbThread(), so it will crash if it is called and we could fix, such places
4. It is left to the debugger plugin implementation to decide, what to there, if you feel we need to add default implementation say so
5. Manager::Get()->GetDebuggerManager()->GetWatchesDialog()->UpdateWatches();
6. It is common for all of them.
It you feel we should use pointers everywhere in the GetSomething API, please say so, I'll make a patch... My style/desire is to use references whenever is possible, but looking at it now probably pointers are better here.