I'm not laughing, but I am grinning.
Sometimes it pays to be the richest house on the continent.
And he hasn't drowned anyone... yet. There will be a lot of bile churning in the Westerlands, the sort of resentment that lasts centuries. Dreams killed or left stillborn. Lost gold scarcely dulls knives.
You are right, but now he can literally buy loyalty, by offering to forgive debts if his vassels do things that he wants... like a fort or two here or a hundred men at arms to garrison there. His position, if he doesn't fuck everything up, is secure.
But Tytos has plenty of chances to fuck up.
Which doesn't mean that he isn't in a dominant position. He is. Many he left poor and has improved his relative standing towards, the rest he can dictate to until coin changes hands. They were already one of the most centralized governments in the known world and... now? They are verging on what the French had when they were at their most utterly terrifying. Their monarch has them by their balls and is squeezing. Where Hoster Tully and Luthor Tyrell have to negotiate, for now Tytos can dictate.
Tytos might be too kind to dictate things from his vassals unless he believes it's for the good of the realm. Now obviously, what he thinks is good and what his vassals think is good will be subjective, but he can clearly do a lot of good, or bad to the West.
And all the kingdoms have taken notice of his power move.
But the pendulum swings both ways and he'll have to be prepared for its return. This probably increases the chance of a marriage to another realm, though, unless he has a few big vassals who actually were fully loyal to him. He needs a little extra something if (or when) blades are drawn and he doesn't want to hand out hostages.
Good thing he has plenty of sons and a daughter to marry off, plus an entire branch he can adopt in and use as his bargaining tools.
He ain't hurting for marriage alliances. it's the possibility that no one will take loans from the family anymore that might put him into a bad position. But if he forgives the right people and keeps the right pressure on the right people, he'll be fine.
He has earned his son's respect here, hasn't he? Tywin in canon never doubted his love, and now... even if he still has veins of weakness... history will not record him being a failure.
I think Tywin will try to... maybe even emulate his father.
Which may lead to a kinder, less ruthless Tywin.
I just threw up in my mouth a little just thinking about that, so shit may happen that may still make him harden up. I heard Ninepenny kings are fucking around in Essos.