Some quick notes.
Starting with 4u4 leaves the rest of the structure weak, and going for column 4 is more difficult. 4u3 would be a better start, to be followed by a play in column 2 probably.
Rebexus taking 1st player also looks questionable as the blue plays don't line up, and it may be forcing an attempt at a blue monopoly, which is highly draw dependent. 3r3 would have been better.
I do like Rebexus staying flexible by dropping the white tile.
Morel's moves look fine, as I would play.
Round 2 looks mostly fine, though I'd have considered playing the 1b1 instead of the 3u1.
Round 3 starting with the white is too rushed. I'd consider grouping the blacks in the center to make forcing moves for rebexus.
And again instead of 2r2 from the center, I'd take it from the plate to merge the blacks.
Leaving the whites in round 4 allowed Rebexus to get a second column. With the amount of white and blue left in the back, the whites should have been floored.
Round 5 in the last plays should have taken 1u4 instead of 3y3.
