OK, a few more thoughts might be in order, since I find them interesting, too.
1.) They built pyramids like most other Berbers. Appears to be a habit of the Afro-Asiatic speaking groups of North Africa. Maybe the Egyptians started it and the others learned from them, maybe not. Berbers are said to have had a close relation to their ancestors and their spirits, i.e. prior to their conversion to any monotheistic faith. It´s this Berber faith that brought forth the oracle at Siwa, much farther in the East. Of course the Guanche will have sported a somewhat different variety maybe, given the distance and their insular isolation, but maybe the analogy is still enlightening.
2.) Colonising the other islands in the ocean only makes sense if your civilization works like the Polynesian one. We don`t know when and why the Guanche arrived on their islands in the first place, which is maybe why we also don`t know what stopped them from going further. Their civilization obviously worked in a different way; the colonisation of the Canaries was the rare exception. Changing that may imply changing A LOT about them.
3.) If the Guanche get more maritime, then a settlement of Madeira only makes sense as a stopover, Cape Verde only if they trade with Africa, and the Azores or even the Taino / Carib not at all. If they get more maritime, the most likely option is to start interacting and trading with what is today Morocco, Portugal, Spain, maybe Senegal, too. In the latter place, there was also still space for settlement. Guanche / Takrur interaction could have been interesting.