I've been running my S corp since 1997, have started two others in that time, and can give my take. I file my own quarterlies, and the annual 1120S and K1s. I also do my own 1040. I'm not a CPA and this is not to be construed as tax advice.
Your understanding is good. S corp pays no (federal revenue) taxes on income/profits, profits get passed through to shareholders on their annual K1, according to their % ownership (which is determined when you create the company - total # of shares and # of shares each person owns). Note stock ownership determines % ownership, not officer titles. Distributions (profit) can be paid throughout the year to shareholders (again, according to their % ownership).
The key to understanding the salary issue is profit. The IRS requires a 'reasonable' (read: Market value) salary to be paid for the work BEFORE distributions would be expected. Distributions would only be expected to be paid if there was profit (which would be AFTER salaries. There is no profit if salaries are not being paid). Distributions are similar in concept to dividends in a C corp. So if the company will not have a profit on the 1120S, why would it have paid distributions? Therefore, before any distributions are considered, be sure all employees (including officers) have been paid market value for their work.
If you break even (by chance or by reinvesting within the tax year into supplies, etc), or if there is a loss (which would give you a nice deduction on your 1040 and would mean you put money IN, be sure to track your basis), then there is no profit and no distributions. THEN, whether you pay yourself a salary is a matter of whether you can afford to. If the business is operating at a loss, there may be no money to pay. Lots of business owners donate their time for free to get things going, sometimes for years. There is no requirement to pay yourself a salary when there is no money to do so, or if you would rather put the money back into the business. Salary only becomes an issue once profit starts getting handed out in the form of distributions.
You are free to execute your business plan as you see fit, including if that means reinvesting all the 'extra' money and working for free. The issue to consider here is if a business runs a loss for too many years, the IRS may come looking. I've heard this but don't have any concrete data about if or how many years. Generally speaking I wouldn't personally be worried about 2-3 years of losses after a start up.
Note that if you leave the money 'sitting' in the corp bank account, it will be counted as profit and passed through on the K-1. I like to leave a couple months payroll in the account just to be safe at all times. This money would have been taxed in whatever year it was received (I'm on a calendar fiscal year) and can float forevermore. Likewise, expenses are deducted in the year they occur, so if I have a big year, I sometimes in December pre-pay recurring expenses for a year or two, or order extra supplies in Dec etc. Note that equipment purchases require depreciation, Quickbooks/Turbotax does that for me.
As a side note, I can say that S Corp has proven to be an amazing tax advantaged structure for me over the years and I highly recommend it. It's true what they say about corporations not paying taxes. Also, I used to pay $1500/yr for an accountant to do the 1120S and K1, now I do everything in Quickbooks including payroll, and I use turbotax business for taxes. My business has a fairly simple transactional footprint though, if it were much more complicated I might outsource.
Last thing that comes to mind- S corp requires annual meeting notes and no co-mingling of funds. I have a business attorney who keeps my 'binder' with my annual meeting minutes. And I'm very careful to keep business accounts/cards strictly business. If there is any co-mingling of funds the IRS can take away your S corp status retroactively. When I started out, I had a CPA who filed my quarterlies, 1120S and K-1 until I learned how things should be, and Business attorney who helped me establish best practices for a few years. Well worth it, esp in the early years when there is no time. Good luck.