Can I be sued for creating a marketing tool(bot)?

1) By the site, yes, if the TOS provides for suits for breaking the TOS, and no, if the terms just provide that you lose your account. Yes, someone else can sue you for infringement if your bot infringes, invades privacy, tortiously interferes with anyones' contracts, defames anyone, etc.

2) Can you be sued for selling a free program? Putting aside the fact that that's a logical impossibility, if the TOS forbid marketing what you want to market on this site, then the site may use that reason to shut down your account and take further action against you.

Whether they'd be successful is hard to evaluate without reviewing your program and the site and its TOS, but you can be assured that a suit mounted by a social networking site would be problematic for you even if it lacks merit, and is something you need to try to avoid.

If you want to do this, you should put together a proposal for the site of what you envision, but don't expect them to allow you to add applications to their site and assume its monitoring functions. But perhaps they'll make you a buyout offer. To prepare for that, make sure you've protected your program with the proper copyright. Because this technology exists is other forms, you're best off consutling with an IP lawyer to see if what you've created is even protectible, and if so how best to to it and how best to offer it to this site or elsewhere.

Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.

It depends of the TOS. Read it and it will tel you the consequences of breaking it. Perhaps, if the application is useful, you may want to contact the company and discuss its for mutual benefit.

Nearly all TOS' ban the use of automation and any third party code without prior approval. Moreover, most site operators are keenly sensitive to the use of bots of any kind that may have unintended or negative consequences for its user base and its site operation/architecture. Using this bot without approval can and likely will get your account banned from the site. And while you may not be sued under the TOS for distributing this app to third parties, it can lead to your ban from the site under the TOS. If this site is pertinent to your industry, I recommend that you do not jeopardize your standing in that community and consult with them first.

I hope this helps.

Disclaimer: This answer is for informational purposes only and does not constitute general or specific legal advice, nor create an attorney client relationship.