I have never been able to understand the hall/church divide within my 'church' and, in all honesty, I am more confused now than ever.
Why why why can we not just be ONE body (ie, a church) that has halls for hire? Instead we have confusion over which money come sin for what, how to divide up time between the two; insurance policies aaaaagh.

My initial thoughts are that we should indeed try to pay a greater percentage of our parish share to the Diocese, BUT that we should also look into abatements/re-calculations and try to get a smaller bill.
That way, any increase in payment we can make will be a higher percentage of a smaller total.

Since 2005, we have only paid 60% of the money we are allocated

I would suggest though that we don't necessarily make any compromises yet that are not being asked of us.
In my (limited) experience, the Diocese moves slowly on these matters and while it will benefit us to make up some of our short fall, I don't believe we should over commit until the red bills come in. I genuinely don't think that people 'gave in grace' just so that we could catch up with our parish share

I also agree that the 'reduced' rates aren't doing us any favours. But I should say (and I think this is known as it is a point I have made before) that I have never felt that we value our halls highly enough and don't charge enough for their hire.
My own opinion is that if the HELP project considers itself to be independent of the church (which I understand it is?) then the HELP project needs to look at how it is financed and what the realistic costs would be if it operated from other premises.
But I can see that it would benefit the church to give money BACK to the Project (or any other charities operating within our premises), instead of not receiving it in the first place.
I do feel that such an arrangement would also be more realistic for both parties.

Finally for now it is my opinion that the story told by our accounts in recent years has been rather negative in a kind of tail-wagging-the-dog kind of way, and I want to look at this.

My own attitude is one of confidence, faith and a clear vision of a bright future. In much the same way that we celebrate the people we have and the human resources available to us as a church, so I believe we should celebrate our financial resources (as it is given to us by the grace of God) and be seen to actively spend our money in ways that are seen to be of long-term and strategic benefit to the church. This will make the people who give feel that we are using their money to good effect, and this in turn will encourage them to give more than reminding them about how much money we still don't have.
It's a kind of speculate to accumulate thing, and we, being a christian church, need to show faith in that.

It should work in the same way as 'doing work' around the church, or giving useful items for different purposes, or praying with people.
The more we can see each other doing this or that, signs of commitment, then the snowball effect will ripple out and others will catch it.

Because financial givers DON'T see to what level others around them give, it becomes even more important that we (the 'management') show this in some tangible way. Especially if regular giving is up by as much as we suggest. A return on investment will be expected.
By this I mean taking care and being seen to allocate some, regular money to 'fabric' and 'stuff' instead of apparently letting the money just 'disappear'. People are very encouraged by 'things' like new speakers, new candlesticks, new shelves, new children's resources, new printers, concerts etc (which all help with our hiring potential) They feel motivated when their suggestions are met with responsible action and are therefore more likely to give again. Investment and spending is infectious - carefully managed it can be like fresh water and sunshine.

Ours is a very personal church, structured (and I use the term loosely...) in a way that allows the quirks of its members to be welcomed, celebrated and used to great effect according to God's will and ways. We are very rich in that respect and openly 'spend' that currency because of our belief that the well is constantly being refilled.

Money is just another resource of the same kind.