No, your question is not too specific, but maybe not specific enough.
You are using DNN Nav and not Solpart, right?
I've had problems with DNN Nav getting it to behave in regards to vertical alignment of the text, too, but never had an "aha! that's it" solution other than adjusting the top padding or top margin on the text to mimic the alignment I needed. Setting a height and vertical-align in the css never got any result in vertical-align to actually align properly even with padding and margins set to zero, but may have had more to do with other css settings. I've had issues before with horizontal alignment of a single separator (no left or right, just plain separator) and had to actually go with display:block and float:left in the classes for the root node and separator both, just to get them both align vertically the same. It's tricky and touchy to say the least, and with the css there are probably many different approaches you can take.
As far as the menu text not having enough space between it and the separators, you should be able to accomplish this by adding left and right padding to the root node css class.
I've not done a tab type root menu myself, so I've no examples in my personal arsenal, but it sounds like you are off to a good start, hope this helps at least a little.