Where might we find these "collective messages received through the prophets and apostles"? I'd rather study them for myself than ask you or anybody else. Is Joseph Smith a prophet? Isn't he THE prophet? Should I not trust his writings? Do you, or do you not, believe that he is a/the prophet?
This question has a lot of nuance in it to adequately answer it, so I'm making it it's own post. I'll start with the big picture then come back and hit each little question. Obviously these are my views and I acknowledge and respect other people have different views.
God Himself is the ultimate source of Truth. If you have any questions about anything or want to know if something's true, go ask Him. Don't just take anyone's spoken or written word blindly. Always start and end with listening to God directly.
Now, God does use flawed men to deliver His words and act as His prophets/apostles. This doesn't make any prophet/apostle automatically perfect in any stretch of the imagination-- the only perfect man who's walked Earth is Christ. Scriptures are full of examples of prophets/apostles falling short. So yes, these people serve God and deliver His words & are super-important, but that doesn't mean they're perfect and we shouldn't idealize them. Again, always start and end with asking God directly.
The above applies to any prophet/apostle, but since you asked about Joseph Smith I'll answer about him particularly (though this answer would be the same for any other prophet too).
1) Yes, I do believe that Joseph Smith was a prophet and served as God's mouthpiece (when specifically serving in that capacitance)
2) No, I don't believe that means he was perfect or that everything he said/did was perfect by ANY stretch.
3) No, I don't worship his nor am I his disciple (unless you also want to count me as Moses'/John's/Pater's disciple too). Those men are imperfect servants of the Master, not the Master Himself.
4) Nor do I blindly accept anything he himself said just because he himself said it. Those things I do believe are not because Joseph Smith said them, but rather because of my own asking God and studying things out. Always start and end with asking God directly.
Is Joseph Smith a prophet?
Yes.
I'm not sure what you're asking here. He's one of many prophets throughout the ages.
Should I not trust his writings?
Take a specific point and ask God Himself about it. Don't just blindly accept a man's words.