You can call it worship, veneration, whatever you want. The fact is, the Hebrews didn't make a fine distinction between worship and veneration, the term generally translated as "worship" is used in Genesis 33:7, Genesis 42:6, and Exodus 18:7 (but in these contexts most English Bibles with translate it as "bow down," "venerate" or "did obeisance"). You probably think Joshua 7:6 is idolatry of the Ark of the Covenant. The distinction we make between veneration and worship is according to your terminology, we use "worship" today mainly to mean rendering religious service on par with sacrifice (although obviously we don't use any Sacrifice, Christ offered the final one, but there is a particular relationship expressed by that, which we use worship to mean). If you want to say we "worship" angels or saints, that is fine if you want to use the term "worship" like the Hebrews used it, or how it used to be used in English ("Your Worship", for instance), which was just meant acknowledging great worth; the King James Bible translation of Luke 14:10 reads, for instance, "But when thou art bidden, go and sit down in the lowest room; that when he that bade thee cometh, he may say unto thee, Friend, go up higher: then shalt thou have worship in the presence of them that sit at meat with thee." If, however, you mean "worship" in the sense of service to a deity, obviously we only do that with God the Trinity.
The truth is, entreating someone isn't idolatry, and never has been. It doesn't say that anywhere in the Bible. Entreating demons would obviously be wrong, though.
Yes, prayer has several meanings. You define it narrowly as "beseeching God", and therefore say those who pray to saints or angels, make Gods of them. No, we just don't accept your definition, which is quite new, and hardly the only one.