First! Just kidding. Could anyone tell me if this is an ok primer to learn Ukrainian while I wait for the Russian course to become available or should I just stop now?
This is what I have to say to you: If you know Ukrainian, then it'll be easy to learn Russian, but definitely not vice versa!
It is not 'way' more difficult, but it is more poetic in a way. Both languages are very complex and are hard to learn fluently, but Ukrainian does have more to it. It has a more poetic range of words and is less commonly known, so there is a smaller opportunity of speaking with another foreigner or learner of Ukrainian to help improve, but it is a very nice language and it is definitely worth taking the time learning.
http://masterrussian.net/f42/ukrainian-russian-alphabet-diffs-3689/ This has some good information on the alphabets. I believe the alphabets are mostly similar so you should probably continue.
Probably because of what it says in the notes at the beginning of the lesson: the present of "to be" is rarely used in Ukrainian (the same goes for Russian, I believe)
Why, copular deletion of course!
In quite a few languages, when a noun is being linked to something else, be it another noun or an adjective or whatever, the copula (to be verb) is omitted.
In English, when you refer to Dad, (or Mom) how he's called by his children, it's a proper noun, like a name, so it's capitalized "Dad." If you're talking about "my dad, your dad, his dad," etc., then it's just a noun and stays lower case. In Ukrainian, it's always lower case тато, right?