Making progress, but now User Review is not being cleaned. Not only is it replacing special characters with codes, it seems line feeds are being removed but not replaced with a space.
Regardless of the inability to get User Review from the main page, I think getting it from the review page is best anyway. The main page user review is placed there by a script, probably so it can be rotated. If the plugin could get it, it would result in the review arbitrarily changing each time it is run—not necessarily what we would want. The default review page, however, places the "best" (based on the number and proportion of users finding it "useful") first. That's likely to result in a better quality review, and might even avoid the really crappy ones.
As for Tagline, there often are multiple items on the taglines page. But I must disagree with Ivek's philosophy that every bit of data at the source should be downloaded. The purpose of the program is to gather a reasonable selection of data that is consistent and of the best available quality. Notwithstanding some movies have a number of (possibly equally prominent) posters and taglines, most have just one, or one main one. I think the only choice is to trust whatever judgment IMDb uses to decide which one goes on the main page. It's not hard to find examples suggesting that judgment is not sound, but I don't know what choice we have. There doesn't appear to be any basis for determining the "best" choice from the taglines page.