I don't exactly get why this new start is more effective than the current starts. In fact, the role of ADC-support lane prescribes that ADC don't buy wards at all.

Just reached home to my computer, so here's your downvote and the obligatory explanation as to why I think this idea sucks.

The biggest problem with this setup is that not only will the support be behind on items, the ADC will also be behind on items. An all-consumable start for the ADC is never a good idea, as he will be some 400 gold behind his opponent in terms of items. That means he's (most likely) going to be at a disadvantage once his consumables run out.

What kind of item start are you looking at for the ADC, exactly? Red pot + 3 wards? Red pot + 2 wards + 2 pots? How long do you expect the ADC to keep buying wards for? Every additional ward bought is a stumbling block in the ADC arms race.

The cons being laid out, I don't think your setup offers enough pros - ie a tangible enough benefit in the lane. Frankly if I see an enemy ADC start red pot, I'll know to be wary of going all-in on him. And needless to say, if the enemy lane plays warily, then you lose the lane.

And you aren't seriously suggesting a blue pot start on Soraka are you? C'mon.

Looks like I shall be the first one to tell you that this is a really stupid idea.