I totally agree that the system needs an overhaul, so below are my thoughts.
I've heard that the process in England and Wales is not that different to Scotland, except that the seller gets all his paperwork in order before the property is marketed. So rather than wait weeks and months for paperwork to arrive in dribs and drabs, it is all there for the solicitor to do their due diligence from the off.
We tried the HIPS, but sellers didn't like paying for surveys etc before marketing.
I think everything needs to be provided early on (with the exception of a survey, which still should fall to buyer's to commission). A large proportion of delays is waiting for the seller to provide ID documents, fill in the protocol forms, waiting for the buyer to pay monies on account for the searches, waiting for mortgage offers, waiting for management packs, waiting for certificates/warranties, waiting for the searches, waiting for redemption statements etc etc.
If a lot of the preliminary work could be done prior to marketing, then this would cut down a lot of the delays and mean that buyers/sellers could be contractually bound a lot quicker than at present. It would weed out flaky sellers who won't put their money where their mouth is.
It would also mean that giving timescales/discussing exchange and completion dates could be much more accurate and sooner, when the solicitor is in possession of the paperwork.