1- I know this sounds like a cliché, but I really think you're too focused on the label of each shool, rather than the dharma of each school. Even within theravada there are differences in the dharma that is taught. I like to think of the word "dharma" as the "truth that sets free". In that sense, all schools of buddhism have a lot of the truth that liberates.
I also personally identify a lot more with theravada. But I think all schools evolved in some direction from the original teachings of the Buddha. This is just my personal opinion because I don't know the original teachings. But what it looks like to me is that theravada evolved in the direction of perfectionism.
The best example I can find of this is how the interpretation of jhana changed in the perfectionist direction. The orthodox view is still that, while in jhana, there is no volition, no perception of the body and no perception of the senses. I think the same thing happened with the ideal of the arahat and that ended up influencing how nibbana is conceived. If this ideal arahat doesn't feel anything, or just feels the jhana factors and brahmaviharas, then nibbana must be understood as some kind of flat, emotionless state. So parinibbana will be like spiritual suicide. And that, in my opinion, is ridiculous. Because if that was the case, the Buddha would clearly
Bhikkhu Bodhi, who is one of the most respected schollars of buddhism, doesn't believe this and he has an article where he explains his position against this nihilistic aproach that became the perfectionist orthodoxy. (google is your friend and will find you the article)
2- As I've said in a previous thread where you complained about this subject, practice both shikantaza and your theravada method of choice. Since you like shikantaza, then do it because that makes you enjoy the path in the present. That is crucial. Since you believe the theravada doctrinal framework is the best for your future attainmemnt of enlightenment, then also practice your theravada method for your future enjoyment.
"He turns his mind away from those phenomena and, having done so, inclines his mind to the property of deathlessness: 'This is peace, this is exquisite — the resolution of all fabrications; the relinquishment of all acquisitions; the ending of craving; dispassion; cessation; Unbinding.' " - Jhana Sutta