Strange formatting

I have just noticed, that the formatting in the posts is not very consistent. Apart from strange rules concerning what goes in bold and what in italics (which is completely my fault, since I keep forgetting what have I decided), the line spacing in different paragraphs tends to change according to some random rule. Sometimes the lines are quite tight, at other times they give good 1.5em of extra space.

I guess this has something to do with this blog running on Blogger Beta version. Hope you don't mind.