Much, much better.
You can consider thinning the low power traces between the opto and the power triac, they only carry a few mA, and that will help with your clearance. Extra credit for keeping the traces from pin 6 of the 3041M, and R6/R7 to the north (in the drawing above) of the keepout area. You want to maintain as much separation as possible between the two sections.
Whether to ground the mounting holes depends on what you are mounting the board to, and what with. However, I would not ground them using a thin trace back to your low voltage section, that is not a good safety ground. That thin PCB trace will look an awful lot like a really bad fuse, when you need it for safety reasons.
If the thing you are mounting to is conductive, then you can rely on that to ground the fasteners.
If it is a non-conductive mounting surface and your fastener is metal, then yes ground it, but consider adding a safety ground connector and not doing it through a thin pcb trace. You can consider eyelets connected to grounding wire, or thick PCB traces to another pheonix terminal block just for safety ground.
Or you can use non-conductive fasteners.
Lots of options to consider.
WRT the rating of the snubber components, the boiler is probably ~10A, but mostly resistive, the pump will be much lower, but inductive. If you err on the side of higher wattage, there’s little to no downside for you, because you are not pushing this into production, so the extra cost of the part is meaningless. Make sure you use flame proof/retardent high voltage resistors, and X2 caps in the snubber circuit (from the footprint, it looks like you are already using X2 caps.)