1. "cease to be of an issue" is wrong. It should be "cease to be an issue". Presumably a typo.
2. I would only use "too much" directly with uncountable nouns ("too much cheese", "too much effort", etc.). "Burden" is, to me, always a countable noun, so "too much burden" is wrong; it should be "too much of a burden". Google search suggests that plenty of people don't agree with me though.
3. Either is fine, but it should be "a role in", not "a role on".
Your question is phrased OK, but (sorry, very picky) you have a spurious double space, you don't need a space before the question mark (in my opinion), and I would omit the colon.