It says that the front and rear gardens will be left free of rubble, so I'm assuming they will be cleared.
With regards sockets the contract states 'double sockets, TV and phone point as required by layout'.
I didn't think about the outside tap and didn't think you can request position of the radiators.
My experience is not to assume anything. That is the reason I advised that you should visit the site as often as you can. Your scrutiny might also encourage better workmanship.
Changes and extras are easier and less expensive when the house is under construction rather than trying to deal with them later on.
@metricspaces has explained about positioning of radiators and also has made excellent other points.
In this day and age you can never have enough sockets - number of TVs, appliances, broadband modems, PC/Laptops, printers, lamps, etc. Think about what you have now & what you would like to have in each room and
note it down.
Also think about room design. Wall presses or wardrobes that don't go up to the ceiling cannot accommodate tall objects and the space between the top of the press and the ceiling is a dust and/or grease collector, difficult to clean, paint or wallpaper.
Where will you put pots, pans, food processors, juicers, etc., in addition to crockery & cutlery. Perhaps floor to ceiling units may be preferable.
Find out what
precisely what comes with the builders package regarding tiling, painting, fitted kitchens, white goods, if any, bathroom suites, wardrobes.
Don't assume anything.
At the snagging stage, you won't notice everything at once and so give yourself plenty of time in each room in the house and also the garden before compiling the list. Look at everything from the roof down & ensure that your surveyor does the same.