Agree with your second point about the use of my pic funds and the need to speculate to accumulate.
With regards to the earmarking you mentioned from a while ago who oversaw this? Separately why can't they earmark land for their cities primary sporting asset?
The development proposal had space for numerous office buildings (17 I think), residential apartments and at least one hotel, but did have two originally. It has since changed because they've not managed to get many of the offices built. The government quango ended up next to the Butts instead and the RICS people pulled out. So far the one building has been for the council, who sold their current offices to the uni to build it and try and kickstart the development. The western side has now largely been taken over by a bus interchange rather than the offices originally proposed.
It's being done by Friargate LLP, of which the council is part. Studies for years have shown that Coventry has a poor offering of office space and hotel rooms, especially centrally. But it's also siad the same about retail and entertainment/dining. A large part of that is Birmingham takes a lot of this and Wolverhampton suffers in a similar way.
There isn't anything preventing them earmarking land for the football club (it's what they did with Ricoh as part of the wider development) and it does now seem that it's an owner thing than club thing - they just have absolutely no trust in SISU or anyone involved with them and I'm not sure they think any stadium development would be for the best interests of CCFC. It wouldn't be CCFC's stadium - it would be SISU's. You assume the club would get all the matchday revenues but nothing is certain with them.
The other big issue is that the previous development largely got through due to the larger redevelopment aimed at regeneration while this would be solely for a football stadium. As well as the usual transport links and desire for public transport from central planning policy the land itself needs to be suitable for a top end playing surface, so anywhere with even a potential flood risk etc wouldn't be suitable.
As I said above, it's been shown in studies that Coventry has a poor entertainment offering compared to cities of a similar size, but when an arts venue in the centre etc is suggested it gets rejected because things like Warwick Arts Centre exist and all the offering in Birmingham. It's a vicious circle. We don't have a great offering so people go to Birmingham but when it's suggested we build our own the reports say the demand isn't there so they have to reject it as not viable. So everyone keeps on going to Birmingham and our offering continues to be weak.