Any question answered...

is the ringel s also not part of german alphabet? i.e. 30 letters in theirs?

You mean the "Eszett" (ß). It's controversial. The current official story is that it's part of the alphabet, but I resist that for various reasons.

(1) I don't accept most parts of the disastrous 90s-00s spelling 'reform', which has resulted in a lot of silly nonsense and confusion (and much of it has already been taken back and more will be). A new (and supposedly 'standardised') role for the ß is part of that. I don't think that the ß is genuinely an independent letter, but rather a contraction of (old German writing) s and z, so essentially just a small aid to writing.

(2) The ß has been removed from spelling of German in Switzerland and Liechtenstein. I think it's confusing to include it in the alphabet in Germany and Austria. I'm in favour of continuing to use it, however. And yes, it is all a bit messy.

(3) Traditionally, underlining its nature as merely a short form of two (lower-case) letters, there has traditionally not been an upper-case form of the ß (and it is hard to write one that is in any way distinctively upper-case). Where words in which it occurred were spelled in upper case (e.g., "STRASSE"), the letter was replaced by a double s. As the spelling 'reform' nonsense gave the ß a different role, in which spellings using double s and ß were distinguished by sound rather than convention, it has more recently been felt to be necessary to introduce an upper-case version, but it is not generally accepted. I think it's absurd to accept a letter into an alphabet that has only a lower-case version, but also, for reasons given, inappropriate to invent an upper-case version that to all intents and purposes hardly looks any different from the lower case. Here are the characters for comparison:

ẞß

It's lost on me what in the character on the left makes it more suitable for upper-case use (seemingly just squashing it a bit and giving the upper bow a slightly sharper angle). See the Wikipedia article:

https://de.wikipedia.org/wiki/%C3%9F