On the NDA specifically, I can't quite work out why I would want my clients to sign an NDA for me. Usually, it's me signing one for them. When I work with my smaller clients, sometimes they say things like

"errr, it's super secret, can you sign an NDA before we talk about it",

to which I reply with

"No problem, here is a standard NDA I use a lot, I've already filled it in and signed it for you, is that enough? If not, send me your document and I'll take a look".

9 times out of 10 that's enough for the small clients. Big clients have their own NDAs that I read and sign. So delay isn't really a problem, it's not me that cares, it's them. I always sign and return their documents quickly.

Invoices on the other hand. I don't generally have a problem as such, but smaller clients do often forget. I send a polite email the day before the invoice is due with something like "Just wanted to reminder you that invoice 1234 is due tomorrow. If you've already paid it, thanks." Again, 9 times out of 10, that kicks them enough to get payment the next day. Very very very occasionally I have to send another follow up a week later. But I don't really consider chasing up invoices to be a major problem in my work, it's just an occasional email to remind people. And it's fairly rare, so again, I don't really see a problem with the delays I experience at the moment.

On the subject of requirements gathering. Yes, it's always multiple conversations, but I see that as pretty integral to the process of understanding requirements. I watched the video, and I don't really see that Sieve does that I couldn't do in an email. In fact my initial email exchanges with clients do have questions very much along the lines of the questions you have in your forms. And the example answers I could see in the video show exactly why Sieve wouldn't provide all the requirements in one go. One response to "Summary of your business problem" was "I want to build Uber for Mars". Well yes, that's exactly the kind of responses I do get sometimes, and what follows is typically a discussion about scope, specifics, scale, etc. I don't see how the few forms on Sieve will force clients to actually think and provide the detail. Clients will just fill them in exactly as they would in an email conversation, far too vaguely to be useful in the first instance. So after going through the Sieve process, I will still need to arrange a call or exchange emails with the client to gather requirements details.

Another thing I've just thought of is what jurisdiction you offer services for. For example, the NDA flashed up very briefly, but I caught the word "employer" in it when referring to the client. I'm based in the UK, and there is some legislation known as IR35 that means freelancers usually want to be very careful to make it absolutely clear there is no employer-employee relationship. Now this is very UK specific. So it might not matter to you if you are targeting only the US. But it's something to think about, every jurisdiction has particularities that need to be catered for in legal documents. If you are offering this globally, you'll need to tailor your contracts and documents for each country.

I know I'm being very critical, but don't be disheartened. I suspect that I'm not your target audience. As a dev freelancer, half of your value proposition is useless to me (the personal website part, as I mentioned previously). I'd have a hard think about exactly who you are targeting, the types of freelancer, the types of work they will are doing, and then find some and talk to them. Show them what you have and find out if it's useful to them. In other words, do some really manual leg work first to find your first 10 paying customers. Doesn't matter if it's not a process that scales, because you'll only do this for your first 10, if you can't find 10 people who will sign up by manually calling them and convincing them to sign up, then you need to have a rethink - http://paulgraham.com/ds.html

(This got a bit long, and isn't really useful to anyone else. Shoot me an email if you want to talk me. It's my HN profile)