He was an absolutely horrendous bigot, who created a climate in which men killed innocent people merely for being Catholic. He may not have sent them off to do the killing but he was certainly in the background, whispering hatred in their ears. And he did absolutely everything in his power to stop any form of political or social equality, from the 1960s onwards - leading to a continued cycle of violence for decades to come. Even when the winds had changed and the UUP and SDLP were doing everything possible to bring a resolution, even bringing SF/IRA into the tent, Paisley still stood outside p**sing in.
He did nothing to help bring about peace, merely undermine it at every turn. When it was finally in place, and he faced a fait accompli after the agreement had passed the referendum, he took advantage of the wounds inflicted on David Trimble by years of negotiations to manouvre his own party, the DUP, into a position of power. Even then it took another decade for him to accept a deal.
The fact that he could then sit in government with SF does not wipe out all that he did in the decades before.
Whilst everything you say is correct, there are things in his favour. That his principles could be bought off meant that he would keep peace hostage, but would release it when he got his ransom. Giving him a house and his family titles was a small price to pay.
He and McGuinness should be friends, they have much in common. They are/were driven by murder, with personal prestige and power. This meant they were easier to deal with. A genuine idelogue, rather than hate filled egotists, would have been even worse.
They are hypocrites, but as they claimed that their 'principles' would prevent any compromise, we are fortunate they were lying.