Probably not an issue. Once cured, I don't think it will outgas any more, and it should remain flexible. The true tell, though, would be to read the manufacturer's spec sheet. Baseboard supply lines rarely use more than 200-degrees, and less is much more common.
Unless there's a waterproof layer beneath the tile, the tile installation itself isn't waterproof, but it would take awhile to soak through the grout joints. FWIW, in a shower, the tile is a wear layer, not the waterproofing layer if it is built right. Same thing is true of a floor.