and it gives this for the wild west version:1. Eng. regional (Lancs.). Inquisitive, meddlesome. rare.
1882 J. H. Nodal & G. Milner Gloss. Lancs. Dial.: Pt. II 228 He's a rootin' tootin' sort of a chap.
I suspect that the two are quite unconnected. 'Rooting' in the Lancashire version seems to mean 'digging' or 'delving', that is, poking ones nose into things. 'Tooting' may be derived from 'doing' (meaning 'busy'), changed in order to rhyme.