Tentative. As an alternative, “His Majesty” might be vocative here.
Tentative. See the Hittite root warp- ‘to wash, bathe’; washing rites are attested elsewhere for the statues of deities (e.g. CTH 475) and the context of usage of warpašši- elsewhere suggests this analysis (eDiAna-ID 2753). The form can be understood as a Luw. nom.-acc. sg. n. (-n+sa/za), presumably from a relational adj. formation in -ašša/i-.
Or perhaps: “…will be (i.e. performed in that occasion)”.
Note that the sequence <of that place> + <washing ritual> has an inverted order in the two sentences at ll. 4´-5´ and 6´-7´: the expected order is with the genitives anticipating the head, as in ll. 4´-5´.