The English alphabet has only 26 letters and no diacritics at all — on paper, one of the simplest alphabets in the world to learn to recognize. The real challenge lies elsewhere: those 26 letters don't map consistently onto English's sounds.
Learning the 26 letters and their names takes very little time. The genuine difficulty is that the same letter can represent multiple different sounds depending on the word (the "a" in "cat," "father," and "ago" are all different sounds), and different letters can represent the same sound ("c" in "cat" vs. "k" in "kit").
Unlike German, English capitalizes only proper nouns and sentence-starts, not every noun — a comparatively simple rule with far fewer exceptions than the pronunciation system built on top of the same 26 letters.
26, with no diacritics — one of the simpler alphabets in the world purely in terms of letter count.
Because those letters don't map consistently to sounds — the same letter can represent several different sounds, and different letters can represent the same sound, depending on the specific word.
No — only proper nouns and the start of sentences are capitalized, a simpler rule than German's capitalization of every noun.
Not yet — English is planned for a future course. Contact Tarc to be notified when it launches.
See also: English Pronunciation · Learn English · German Alphabet