FormerFP-G:

But the loan cant be challenged under any form of CCA as its non-reg, over £25k.

to answer some of your points:

2) its impossible to get any form of loan that isnt interest front loaded
3) Making capital repayments is allowed yes. its stated in the T&C's of the agreement about interest charges. Might not be interest charges if you pay below a certain value, might be 10% of the loan balance?
4) Redemption charges are not an FP thing, its something that is allowed under the regulations on early settlement by the CCA. some accounts are rule of 78, although yours does sound like its 6 months interest + a security release fee/admin charge. again its on the front and back of your credit agreement.

SAR will cost you a tenner, dont bother. you can get a copy of your CA free from them. just ring and ask for it.
They arent being obstructive, just sticking to the T&C's that they, and yourself agreed upon (im not saying that they are ethical,illegal fair or unjust, just stating its a contract that the borrower had ample time to get checked out before commiting, and also 30 days after payout to cancel the deal.

Sorry to be picky but the request under the CCA 74 Section 77 cant be made (not valid) for unregualted loans. So the £1 option is not an option for over £25,000 loans. Wigeon