When a name is in a title, they are often rendered in kana even if kanji is available, especially as kanji for names can be read differently.
And katakana is often used simply as a stylistic choice, to make it "pop" so to speak.
ムカージ sound a metathesis to me. I mean it's bit hard for to distinguish ムカジー, ムカージ,ムカジ. Without the elongation ー between カ and ジ is the most natural to me. (i.e it sounds ムカジ to me.)
As for 1. We do not distinguish Va and Ba. So it's more close to Wa as you think.
As for 2, if you want to avoid "Liaison", I think ム is easy to separate your given ...