Q:

Verb +～そう grammar

面倒な手順の方が成功しそうじゃない？

What is ～そう ? Is is the contrary of ～そうにない ? So it would mean something like : "It's likely that you will succeed if you do it the hard way" ?

A:

https://www.italki.com/question/353833 
https://dictionary.goo.ne.jp/jn/129025/meaning/m0u/ 
"～そう" means "it seems", and "～そうにない" is the negative form. 
More literally, your sentence would be "Doesn't it seem likely that you will succeed if you do it the hard way?", with "じゃない?" meaning "doesn't/isn't it?" here. 

