Yes, good point, the term spirit, in and of itself, can have several meanings and significations.The way I see it, the term "spirit" just means something that isn't bound by the laws of our physical existence. It could be referring to anything present in 'heaven', that exists as a spirit being, or was created as one. The extent to which these beings aren't bound to the laws of nature is determined by the one who created them. Surely, them being "spirits" doesn't automatically qualify them as equal to God in limitless power. We are spirit beings ourselves after all, who are made 'souls' by the union of the spirit with the body, yet we were designed as lower than the angels in capability. This is why the term "spirit" is such a vague term.
In the context of God Himself, as being Spirit in ontology, in regard to defining his physicality, it is intangible, uncorporeal, cannot be circumscribed, is outside space and time, and therefore, cannot be defined.
He is invisible to all creatures, and unapproachable, ...and I really don't care which Biblical character 'saw' Him, spoke to Him, wrestled with Him, or ate in His presence. More often than not, God sends His angels to undertake any creature interactions, although they may be referred to as God Himself. Which is permissible, i.e. to refer to the messenger as the Agent, but the converse is not acceptable i.e. call God an Angel. Or, God may cause an effect in nature on occasion, just to assure man that He is watching over them (clouds & fire during Exodus).
Either way, if God has created the universe, which He did, we expect that His presence, or any attribute or characteristic that He may have, is much larger than that, and therefore, beyond description and comprehension.