Didn't reach expected FG. Should I postpone bottling? Also: It looks weird!

I'm a newbie brewer currently trying his luck with an irish red ale kit. I've followed the instructions (which weren't complicated since it's a kit), and I've let it brew for about 6 days now (instructions claim 4–6 days to completion in 18–20°C).

First question: The inctructions say the ale should read constantly below 1.014° when it's done, but I measured it to a bit above 1.017° both yesterday and today. I checked the temperature today, and it was 17°C. I don't think I've treated my yeast particularly well temperature-wise; the weather here and my lack of any real temperature control has probably lead to temperatures between 16–22°C (it was probably too warm when I began brewing, and too cool the last couple of days).

So I'm wondering: Should I heat it up to 20°C and let it sit a couple of days to be on the safe side, or should I accept the slightly higher gravity reading and just bottle it?

Second question: I noticed that after the krausen disappeared, there are theese brown floaters on the surface (I'll add a picture), almost like some of the dry yeast clumped together. Does this look normal, or did I manage to get an infection on my first attempt at beer brewing? (It doesn't smell off at all, if anything it smells surprisingly sweet, almost wine-ish.)

I'd appreaciate any input. Thanks in advance!

Edit: As a final update, I thought I'd post how the beer turned out. After leaving the beer alone for quite a while, the gravity remained stable at 1.015°. I've no idea why the FG ended up too high. (Thoughts, anyone?) Anyway, I bottled the beer with carbonation drops and let it sit in my basement for about two weeks before finally tasting it.

The beer turned out pretty good, though a bit too malty. It carbonating nicely, ruled out dead yeast as the culprit for the high FG. Another week later, the beer tasted even better and not as sweet; it seems another week in the bottle did wonders for the taste (patience coming back to bite me in the arse again). It has a nice fruity character, but is still bitter enough to keep things balanced (at least after the third week post bottling). I'd describe it as interesting and refreshing, and it has a pleasing tawny red colour.

All in all, I'm a very happy brewer at the moment, and I look forward to my next batch (a helles lager). For those of you who are interested, I used the St. Peter's Ruby Red Ale kit. Happy brewing, folks!