And yes, getting support from amd making apologies for a country like Russia is a good signal of who not to want anywhere near the halls of power.
If any of the parties got any support from Russia directly, they would be arrested. Have they been arrested? If not, then whatever you've been told about them being involved with Russia is bullshit. The government would like to find any excuse to lock up certain individuals in the UK; this includes both those on the left and the right.
You're taking "innocent until proven guilty" too literally. Absence of evidence isn't evidence of absence.
You should demand evidence for claims, especially if they are serious as you claim.
I also have very little respect for people that justify violence because they believe they are morally righteous. Doesn't matter whether they are left/right, Muslim, Christian, Jew, Hindu, Buddist etc.