I think you'll find that refueling isn't allowed this season. Tyres wear so need changing but there are rules and restrictions on their use. I as far as I can see the driver's skill is always the deciding factor. I doubt any of us could drive an F1 car out of the pit lane let alone race.
Harder tyres then... 
I am not looking to prolong the argument but the new roolz do state that they MUST use both hard and soft compound tyres during the race so at least one tyre change is mandatory. Exceptions can be made, at the race stewards' discretion, in the event of rain during the race.
As far as I understand it the rule changes over the last 10 years or so have been driven firstly by a desire to prevent death and/or serious injury but latterly the impetus has been to try to even out the technical superiority of one vehicle over another and make it more of a driver skills competition. Of course the "teams" have resisted this as they know that a tweak here and there, using modern computer designed equipment, can make a difference. At the end of the day it is the motor manufacturers who want to sell more cars that put up the money to prove that their vehicle is superior. Many of the things, ABS, Power Steering, etc. that we take for granted and have all become common place on the cars we buy, have first been developed for racing cars.
All that said I still maintain that the chance of a "pile up" is the main reason most of us watch what has become, for many, only marginally less boring than listening to snooker on the wireless. Personally I'd rather watch horse racing or a game of football and I am not that fond of either sport but they do still depend on the skill of the riders and players far more that the latest bit of technology.
