Will this strategy work with an affiliate store?

Im thinking to create an affiliate store, i don't plan to include a blog, only products and reviews of them. The problem is that i don't have any budget to invest on paid advertising and seo is slow, im thinking to focus on direct traffic, specifically forums or places where people ask or discuss for products, i will have a link on my signature and make many posts. I plan to sell very expensive products.

Do you think this strategy will pay off? shall i expect any sales at all? Do you have any other strategy to recommend with this plan? does affiliate marketing work with paid ads and blogging only?

Try also growing social channels in your niche

Yes the strategy can work if you provide value in your posts and responses. If people think you are spamming then it won't be effective.
You will find the process time consuming but if you find the right communities and match them with the right products then you might have some success.

IMHO, unless you're a appointed mod or forum owner, you'll get swamped down easily, even if you provide value. Make multiple accounts and grow them, churn some to find what sort of behavior is tolerated and where the tipping point is, than use your 'main account' and act accordingly

This will surely work provided the forum you engage is having large set of active users. Take an example of BHW many buyers buys services by seeing them in member signatures. It works but again the forum must have active user base.

I don't think it work. Rarely people click on your signature link no matter how many post you write. They may only click on the link in the content of you post. If you are going to start an affiliate site, then I suggest to focus on what you know best, write review about that product and write more article to like "This is the best... or comparison of..." to get more traffic.