I am a product engineer and content producer with broad but applicable skills in software product testing and management, and creative problem-solving.
You'll get more passionate, committed work out of a partner who is also an equity stakeholder than you will from an agency or contractor without vested interest. I would just start talking about your idea to people. Honestly, ideas aren't worth that much, and it's all about the execution. Worry less about someone stealing your idea, and focus on spreading your excitement for the product around until you find someone who shares your passion and would be interested in joining you. I would jump on Meetup.com and try to find every technology related event in your area and just start meeting folks.
My only experience is using Zendesk, and while they're great for large teams, their pricing tiers can be frustratingly orthogonal to startup growth rates. You might want to use them for the long haul, starting immediately if your budget can handle it, or transitioning later. If you're using SalesForce for your sales teams, there are support modules there that can handle basic ticketing. It all depends on what you expect your support demands to be in the future.
I would say the best way is to ask questions socially / track their support forums / converse with employees to discover a problem they have. If you can demonstrate that you can solve their problem and generate revenue / cut costs to a greater extent than your fees, then you stand a pretty good shot at getting in.
All companies have externally visible problems, if you're willing to look hard enough.
Pricing for different tasks that require the same amount of time from you tells the Customer (and your subconscious) that you're working at a 5 on task x, but working at a 9 on task y simply because it costs/earns more. That seems to be a disconnect. Your time is your most precious asset, and I would charge for it whatever you're doing. If you build a site, and they are happy with your dev fee, but feel like you should charge less for SEO, simply let them find another SEO guy. That's their choice, but YOU are worth $xx.xx, no matter what you're doing.
Also, in general, take whatever you're charging and add 10% to it. If you're still busy, add another 10%. Let the demand level determine how much work you do, and at what cost.
I think you should first really step back and ask if you need that role filled. Are your sales growing? Are they growing as quickly as you'd like? Do you think someone could push that needle?
I've worked at companies with strong focus on sales and some where there were no sales people at all. It depends on your niche and who your customers are. Depending on your outreach methods, perhaps you need to hire someone with a strong sales background who's going to pick up the phone and start cold calls all day, or maybe you just need someone to handle your marketing better and help you out with some Adwords campaigns.
Business Development is a big term, and it can cover a lot of things, most commonly sales... but salespeople aren't right for every business. So, look at your existing success. What sorts of things bring in the money now... and look to amplify those existing efforts before you go breaking new ground.
You should be looking for someone who complements your existing success and can continue to tell that story, in your existing playing fields, and gradually moving into new areas. I know this was a vague answer, but I hope it helps.
If you're not a coder, I don't know how you're going to publish code... but I'll look past that.
The best thing to do is host the code on Github, then create a website for the project using Github Pages. At that point, gaining traction from the community so other people contribute to it has a lot to do with what the code is, and what it does. A good place to start is with solid documentation so anyone looking can quickly tell what your code does and whether contributing will interest them or be easy.
As the owner of the project, it will be up to you to allow or deny the changes that other contributors make to the repository. That is how Open Source projects are managed. I would suggest learning more about Git and maybe beginning to code a bit, so you can start to see what people are really changing in your codebase. Codeschool is a great place to start if you want online tutorials.
Best of luck!
One option is to provide dedicated support while letting the code be open. There are plenty of businesses that run on open, freely available architecture, and they make all their money by selling a "Pro" plan that allows people the security of being able to pick up the phone and ask a question. However, you have to give away your product on the front end as a loss leader. This is essentially the "Insurance" business model. It's how Circuit City rose and fell. Be careful, and good luck.
Your valuation is whatever someone is willing to pay you for your company. Instagram was bought for ~$1Bn, therefore, it was worth ~$1Bn, whatever anyone else says.
As others have said, your investors define your valuation, and anyone looking to acquire you, even more so. A lot of companies look at revenue, users, and technology IP, but with more companies starved for talent, you should also take your human capital into consideration. An acqui-hire ain't always a bad way to go.
This sort of depends on how established or large your company is, and what you want as your messaging. A good copywriter can certainly help you find *a* "why", though it might not be *the* "why" you actually began with. For example, if a web hosting company got started because two college roommates needed money to pay for tuition, that's a very important story, but it doesn't really sell as a "why". A good copywriter would come in and put some spin on it like "Steve and Dave knew starting their own business together would be hard, so they wanted to create something that would make entrepreneurship easier for others. At ACME web hosting, we make this our mission every day". It's now a great story, and sounds like a caring company... and it can even be true... but it's not actually the real reason the company started.
A good strategy is to cast your mind back to the feelings you had when you started your company. Just write them down as one word emotions, and then on a separate page, write down the emotions you feel about your company *now*. A good copywriter should be able to find a story in there, and help you position your company in the best possible light, even if through rose-tinted lenses.