What would the Byzantine Empire have to do to survive?

[hoplite14gr]

i always thought that religious intolerance and repressive taxation system lay at the heart of the reasons why both egypt and syria fell so easily....after all egypt was economically sound and had on paper at least a significant army.

Yes rapacious tax collectors are a good reason to severe ties with an empire.
But it was Byzantine military defeat that made the separation possible at that time.
Had the Byzantines won at Yarmuk they would still drain the provinces and force religious orthodoxy till someone else in the future
destroyed their army and grab the lands.

Remember they kept the Balkans in the 9th 10th cenruries despite suffering military setbacks and having ravenous tax collectors.

Kind regards