What call tracking platform are you using? Most of them will let you keep you main number (which is likely the GMB #) and continue to show that to the Bots while showing a different phone number to users based off of what groupings you've set up (i.e. one # for organic, one for PPC).

Its like how a Square is a Square but also Rhombus and a Rectangle. Long tail keywords can be any and all of those definitions depending on the moment, your goals and your needs.

In most cases I wouldn't consider a Low Traffic term a "Long Tail Keyword" simply because it has low traffic. But I would argue that Long Tail Keywords are likely to have lower traffic than their short tail counterparts. People are more likely to search using shorter terms and phrases but sometimes a 4+ word combination can be popular. But I would argue that a Long Tail Keyword/term/phrase is likely to be 3, 4, 5+ words long. Can those words be all extremely product specific? Sure. Do they need to be? No. Are they more specific than a one or two word short tail phrase? Yes.

One word with low traffic is probably just a bad keyword to be using. A 4 word phrase with high traffic could just be a popular long tail search. In some cases it will depend on your industry. Some phrases can have multiple meanings. Just because a 4 word phrase has good traffic doesn't mean you need to use it if the first 3 pages in the SERPs are all sites devoted to a completely different concept that happens to have the same phrasing.

Because Google has never broken its own guidelines and then penalized its own pages before.... http://searchengineland.com/google-penalizes-google-japan-16541
http://searchengineland.com/google-chrome-page-will-have-pagerank-reduced-due-to-sponsored-posts-106551