Is the pronunciation of these syllables like...
ん - French nasalized n
Sometimes it is close to it but still quite different. In fact its pronunciation depends on the following sound :
Before g/k/w : velar nasal [ŋ], the sound written "-ng" in English
Before p/b/m : bilabial nasal [m]
Before t/d/n/ts/z : [n] alveolar nasal
Before h/s/vowel or a pause : uvular nasal [N] or a nasalized high or mid vowel
ふ - Spanish b, except unvoiced? Written with the Greek letter 'phi' in the IPA
Yes, exactly, the voiceless bilabial fricative [ф]
ほ - English ha or like Russian kha
This consonnant is closer to the English /h/ than the Russian "kha", which is pronounced with a velar friction. In Japanese, this sound is made in the back of the throat
ひ - English hi or like Russian khi
It's more like the final sound of German "ich", a palatal fricative [ç]
Is any syllable ending with -ya or -i palatalized, like in Russian pronunciation exactly?
They are indeed palatalized, but less than Russian I think