Infections during fermentation are far more likely to occur towards the end of the fermentation & / or if you haven't bottled it once fermentation is complete and the weather is warmer.
If you get some white blobs or a thin white scum on top of the wort, then use a small strainer to gently skim...
I've been brewing with extracts (mostly Coopers) for years. I've just recently been to Japan and I really enjoyed some of their beers which have black and / or red rice added to them (e.g. Konishi Garnet Rouge, Hitachino Red Rice Ale).
I wonder if anyone has added rice to their extract brews...