a) Double Klick on various Column
I added this request to ToDo list (but the time, when I will start to implement it, is uknown).
Program offers good solution: set all columns to your width once only (some of them can be with width 0). Then open in menu Database / Options / On exit and check off item "[x] width of all columns in main table". Then save options and exit program. After restart of program you can see columns width as you set. This width of columns is fixed (program starts with this width every time) until you again check off this checkbox in Options.
b) Is it possible to integrate this ?
Switch position will be possible in future too (I have this planned function in ToDo list).
If you want to hide column, just set its width to zero and save it (as I wrote in previous topic).
c) Display like v 1.3 ?
Do you mean 2 columns for Amount (one for debit, one for credit)? No.
I can set program on sort to don't mix it together (separately debits and credits). OK?
d) Bug or Feature ?
Feature 
When you add transfer transaction, program creates 2 transfer transaction. On edit one of them [eg. date], you edit only one transaction (without impact to second). There is not connection between them. When you delete one of them, the second remains. This is reason, why you can not edit this field (it belongs to second transfer transaction).
e) Enable or Disable "Payee" or "Person" for new entry in Options
Yes, in the future (I plan it too).
f) Enable or Disable visual bold for "Date" and "Amount"
I think you want to write Description and Amount (because Date is bold and Amount not). Fields Description and Amount are OPTIONAL (not bold), others are REQUIRED (bold).
g) Diffrent Icons for Menu and switch to smaler icons
I have too little time to spend it for changing of existing functions (I'd rather to add new functions). But OK, if you send me REALLY NICE set of new icons (now are 32x32 px, so I expect eg. 24x24 px or 16x16 px), I can try to implement it. 
Without time garancy.
h) Remember calculation for Amountbox
I know, for some users will be this function useful and importand. But I have not existing field in database to store it. On the other hand - user can input eg. formula like 1+2+3, after pressing Enter program calculate it to 6. Later user add + 4 + 5 and program again calculate it. What to store, if user did not save transaction yet?
