Ye are not come (ou proselēluthate). Perfect active indicative of proserchomai. There is no word here in the Greek for “a mount” like orei in Heb 12:20, Heb 12:22 (and Exo 19:12.; Deu 4:11), but it is clearly understood since the dative participles agree with it unless they be taken as descriptive of puri (“a palpable and kindled fire “ when puri would be the dative case after proselēluthate).
That might be touched (psēlaphōmenōi). Present passive participle (dative case) of psēlaphaō, old verb to handle, to touch (Luk 24:39).
That burned with fire (kekaumenōi puri). Perfect passive participle of kaiō, old verb to burn, with instrumental case puri (fire), unless the other view (above) is correct.