.Tuopadre.

No she can't, Saryn is not a nuker. Her spores can passively clear rooms in low level missions when fully modded and min-maxed, in Steel Path mode needd so much ramp-up time that the mission ends before they start to deal decent damage over time, whereas Dante could just faceroll on the keyboard and instantly nuke any room at any level on top of giving the entire squad hundred of thousand Overguard. Saryn shines for her weapon buffs and wide area armor strip, and she needs emerald archon shards for that, not for her AoE damage. All things considered, everything you suggested would only make her stronger.

Gauss nuke requires a lot of setup (constant full battery, a lot of energy, priming with heat weapons) and gets cockblocked by most enemies due to Overguard negating heat status. Saryn nuking the entire room was a thing 10 years ago when she used to nuke level 30 and below missions. She is mainly used as a weapon platform and armor stripping now, her 5-10k spores damage aren't gonna clear any SP difficulty room and they wear off easily without adding any LOS restriction. Miasma gets subsumed 99% of the times. Equinox needs to kill to stack enough Maim damage (which gets mitigated by armor anyway), and it's so squishy that dies before doing anything. Most Frames needs to meet some condition in order to perform, wether it is debuffing your enemies, stacking and managing your buffs, building melee combo, respecting LOS, etc, whereas pre-nerf Dante could just do everything from nuke the entire room to giving 60k+ Overguard to the entire squad by simply smashing head on the keyboard. If you can do all that without any sort of downside that's just blatant, unrestrained power creep.

Yes, its perfectly fine facetanking 99% of the game with minimal effort and cost in energy, entire team constantly sitting at 120k+ overguard isn't broken at all.