Better DOM interface that exposes at least insert, delete, setvalue, getvalue
Let these methods have a boolean to defer updates; i.e. if 'deferred' flag is true, then insert/delete/setvalue would set deferred update flags rather than running the rebuild, recalculate, revalidate, refresh.
Although rebuild, recalculate, revalidate, refresh are available, we really just need a simple update() method that either runs all four, or runs the ones indicated by deferred update flags.
The ideal amount of remote control would also allow setfocus, setindex, toggle, send, dispatch... Some consideration would have to be given as to how to do IDREF resolution. The spec resolves IDREFS based on location of invocation relative to the referent. Is that still possible from script?