There were all sorts of references to his plays and parallels with Elizabethan drama in general. I'll agree that Fiennes's Shakespeare was the weak point. But the performance at the end was as good as one could have could have hoped for. And there's the appearance of John Webster which no one picked up on (a schlockmeister known for lurid violent plays like 'The Duchess of Malfi'). Picking Romeo and Juliet as the transition between his early work and great work was perfect. The plays before it were substandard.
Actually, the part about Webster was one of the few interesting things, but a bit to obvious. Yes, there were quotes from
Hamlet,
Twelfth Night,
Romeo, etc., but none of them were done in a particularly witty or interesting way. Having Shakespeare as a dolt could work if it were done right, but that's not what they were going for.
I wasn't looking for historical accuracy, but it is interesting that Tom Stoppard would make all those mistakes. Rosencrantz and Guildenstern Must Die was a brilliant idea.