a few doubts on s corps, home office and accounting

This shouldn't be a problem since you state no sales or profit. You may have to switch in the future if you meet certain criteria.

You may deduct the taxes in 2005 even though you are cash basis (I think it's the recurring item exception),

Yes. Even though you are on the cash basis, using a credit card is deductible in the year of the charge.

Yes. DR - Expense and CR - Credit card liability

I'm not too knowledgeable in this area, so I won't comment. I have a couple ideas on how to do it, but I'm not sure if they are correct.

Also, not sure about which pub, either.

One caution. You state that you have no sales or profit yet. Have you started business? If you have not yet started business, you may have to capitalize your expenses as start-up costs. The start-up costs can then be deducted (in full, or partially - depending on how much they are) beginning in the year you start business.

Remember, you and the corporation are separate legal entities; i.e. you are not the corporation and the corporation is not you. Thus, the corporation cannot have a home office; it has no home. You, as an employee of the corporation can be reimbursed for the home office expenses - in addition to the salary the corporation is paying you. Or, you can deduct those expenses as unreimbursed employee expenses using Schedule A of Form 1040. In such case, of course, the salary should be large enough to cover those expenses. It appears to me that you do not have a real grasp of the corporate structure and the rules that apply to S corporations in particular. I would strongly suggest that you consult a tax accountant for the first year or two to be sure you are getting thigns right. Lanny K. Williams, CPA Nawarat, Williams & Co., Ltd. Income Tax Services for Expatriate Americans

It sounds like you haven't actually started your business yet but rather are in the startup mode. Therefore, you'll capitalize all of the expenses listed above as part of your startup costs and amortize over the appropriate term once you begin your business. See IRS Publication 587 re business use of your home.

The instructions for page 2 of Schedule E indicate a partner can put UPE (unreimb partner exp) on the partner's return under certain conditions. However, no such statement is made for S Corp owners. I don't know if you can take a home office for an S corp, and, if you could, you would probably have to rent it to the S Corp and report the rent income on Schedule E, page 1. It would be a wash-out unless you had a 'rental loss.' You cannot depreciate something you don't own, and your S Corp does NOT own your house, you do. It would not be handled the same as a Schedule C business owner would be able to do it.