Most if not all INSET SINKS , are thinner than the worktop, so NO PROBS!!!
If it can be used either way round (drainer left or right, ) i would position in over the washing machine as less heat is produced above the machine....than the tumble dryer... (even a condensing one)
There is absolutely no harm in putting a drainer section of a sink over other items, in fact the norm of a well thought out design.... as it will allow a better position for the sink bowl itself, allowing easier to install, and maintain plumbing...only muppet designers place a 990 sink directly over 1000 base units, making it really awkward to get to the clips, pipework willbe stuffed tight to a corner etc...how often have we come across this ...groan!!!
my normal method of doing a job like this Lec, is cut out, and fit the main sink, having checked for any clashes of the retaining clips , and tap tails, (remember to really well seal the raw edge of the cut worktop in the sink cut out)... with the worktop and sink, inverted, you can then tighten the clips without killing your self, then carefully turn back over and install, with the aid of a second pair of hands, then install the worktop to cabinets, install the main plumbing, insert the white goods and plumb in the washer.....
an over hung drianer example...
hope it helps....