Antares

That is why in every authentic "pai" there are "heart-mind" purification methods. Which of course must be done correctly. If it is not the case then you can see ego strengthening in a person. My first "teacher" was this sort of person. He taught external martial art -- aikido -- stating this is very internal style and also he taught yang style taiji beginning from iron shirt like exercises. Now i understand there were not any heart mind purification methods. My ego was growing too. In this case energy feeds your "karmic seeds" instead of dissolving it.

Your view on taiji is very limited. Fighting skills are only additional skills for a practitioner. In fact Taiji was the revolution in neidan. Don't forget that Zhang Sanfeng was a student of Chen Tuan. They both played a significant role in the development of the southern style of neidan

I disagree. It depends on neigong system. Some neigong systems are even more advanced than most Neidan school we know nowadays. For example, what about taiji? Is it Daoist or just sets of physical training? Zhan Sanfen is revered as Immortal in China. And I would treat it as more Daoist system than modern Dragon Gate system for exmple But it depends on certain taiji lineage of course, by taiji I dont mean modern yang style variation of it

Can you elaborate on it? What you mean by "trash system"?

I have read his book on neidan (see picture above) and seen couple of his video on youtube re "neidan". There he only states this is neidan but from what i can see he teaches modern northern school meditation (not sure which school) and some qigong/neigong methods from IMA (dao yin for example). This is not certain daoist school methods but mixture of methods

It depends on the school, as methods vary. There is the ancient northern school approach, which is quite authentic and includes dynamic meditations (I used to practice some of them for a while). However, there is also the modern northern approach, which is quite common now and is based on seated meditations. In general, authentic old school methods are based on dual xing ming cultivation, and they include dynamic standing and static meditations, as well as some seated ones. The modern Dragon Gate primarily teaches seated meditation, although they can also teach you some qigong in addition to it. If you want to nourish Yang, you need to move; however, if you mostly sit, it is hard to obtain True Yang. Timing is an important factor in neidan. This is akin to going through the seasons of the year: everything changes in nature, but sitting is like always abiding in winter. Over time, you will lose Yang and thus your Ming.

Qigong may be yes, but even his qigong is questionable. As for neidan he does not have a clue what is real neidan. This is very simplified view on the neidan

What means authentic Shaolin in your case? How authentic is it?

That is the typical issue for those who do the modern northern schools methods