I dig the changes but of course the damage types are the biggest concern here.
Like many others have been saying, switching Spores damage from Viral to Corrosive would limit Saryn's effectiveness across the factions except those with armor.
So perhaps an ambitious change would be that her Spores did adaptive damage to the highest resistance/defense it's affecting. In other words, if Spores were on per say a Grineer Lancer, it would do Corrosive damage to the armor until it was stripped then health would be left so Spores would then do Viral damage. Likewise, on a Corpus Crewman Spores would do Magnetic damage until Shields were gone then Health would be left, so Spores would do Viral damage.
The question then would be is, what would her Miasma do? Her Miasma could do adaptive damage as well, to the extent of what Miasma should be doing; doubling if effected by Spores. These changes seem to fit more under the Virus theme, a Virus that evolves.
Like I've said before, this is ambitious. This is an idea I've had for a while even before this workshop and it seemed appropriate to be mentioned now. That's my suggestion, we'll see how things go.