The red stamps are the official stamp of the temple, similar to a signature.  Often these will use an old or unique way of writing the kanji.  Also the Japanese kanji is from China so there are lots of similarities to Chinese Simplified and Chinese Traditional.  You should definitely visit if you can and take a Shodo class. 

 Damn I realize I need to do a deep dive into Asian languages history 👀 

 So I can develop my own stamp of my “inner temple”? 

 Yes! You can personalize your own印鑑 stamp with whatever design.  Depending on the material and where you get it done it will cost between $30~$500 usd. 

 Basic Japanese from Chinese too 

 I’m not sure what do you mean 🤔 

 Yes 八十八 = 88, it is nice that I can read the menus and get general ideas when I visit China but can't understand full context maybe 5%.
豚 is a common one I see on the menu, just need to make sure it isn't the intestine I am eating. 

 80/20 Rule:

20% of study time to master 80% of the language, and then 80% more study time to master the final 20% of the language.

China will accept 20% while Japan expects 100%.  If you don't speak Japanese perfectly, then you don't speak Japanese.  Even my work's professional translator gets these criticisms. This culture has its pros and cons.  

Also if you think about it can we truly speak any language perfectly?