Should every developer speak on daily?

Are the Developers leaving with a joint plan for the next 24 hours which will get them closer to their Sprint Goal commitment?

No, actually sprint goal is set for middle of next month.

No, theres no such plan for next 24 hours (monday included). 

It depends on how you work. For example, if the team is constantly pairing, does it make sense for everyone to speak? Or would it be better if each pair spoke, which could mean one or both? How about if the team practices mobbing on a single unit of work?

I will say that even for teams that give every individual a chance to speak, a Daily Scrum can still be held in 15 minutes. If it's taking longer, I'd look at what people are saying? Is it directly relevant to the objectives? Or can some conversation be deferred and use the Daily Scrum to plan that a conversation needs to happen, who needs to be there, and when it should happen?

Everyone is working alone as developer. Pairs if any, consist of tester and single developer. There is also no rush, like danger of not delivering. Though few people seem to be stuck.

My problem is at previous workplace we had like up to 10mins of daily and up to another 10 mins of chat after daily (only for intrested parties), and all of that even with 12 people on daily. That's why I'm surprised to see at new workplace it takes 30min chatter alone with developers about major tasks, completly ignoring the other half that is working on lesser tasks. Then I asked myself perhaps SCRUM guide says something about that, yet couldn't find any information is it valid approach or not.

The Scrum framework leaves the procedural details to the people doing the work. The Daily Scrum is an event with a timebox to help focus the participants on the goal.  The Scrum Guide states (emphasis added by me)

The Developers can select whatever structure and techniques they want, as long as their Daily Scrum focuses on progress toward the Sprint Goal and produces an actionable plan for the next day of work. This creates focus and improves self-management.

I frequently work with teams that have a "parking lot" where items needed further discussion are placed.  Then the appropriate/concerned individuals can have the necessary conversations when possible and preferably before the next Daily Scrum.  Since the Scrum event is a Daily Scrum, what I have often said is that the Daily Scrum takes 15 minutes but the Daily Standup could take an hour.  

Actually, this is a good question, I'm the scrum master of a team, and the developers have organized their meeting to discuss their list of items towards the sprint goal, in a way which the meeting does hit the 30 min mark often. Often times the developers list out a laundry list of tickets/tasks for discussion. If this is the way they have organized their meeting, shall I speak up and try to coach them to limit it to the 15 minutes?

A couple of questions for you.

• Do all of the Developers need to be present for all of the conversations? 
• Could the entire team quickly assess their current situation and agree on a plan of work until the next time they meet without having the long discussions?

I had one team of 8 people that were adamant that they could not have a 15 minute standup. I asked those 2 questions to the team and got a "everyone needs to be there" and "the discussions are absolutely necessary" response.  So I started observing their Daily Scrum and took notes over a 2 month period. I took notes of how many people would be involved in every discussion and how often some people never participated beyond explaining what they had learned and what they were planning to do next.  I noted if any of the discussions had impact on work being done by anyone that wasn't involved in the discussions.

After one month, I shared my observations with the team.  What I found is that for every discussion there was a small subset of people that participated and they would be the only ones impacted by any decisions. I found that there were often times where people that had nothing further to contribute nor did they need any help from others. I asked the team if I could start recording their gathering to give them some video evidence. We started reviewing the videos at the end of each week for the second month. They finally conceded that they could do their Daily Scrum in 15 minutes where some of the outcomes were that "Dev A, B and C need to discuss X further after we are done".  

I went to great lengths on this because they would not be convinced until they saw it for themselves.  

 I'm the scrum master of a team, and the developers have organized their meeting to discuss their list of items towards the sprint goal, in a way which the meeting does hit the 30 min mark often.

This seems like they have created an agenda for a status meeting.  If I were you I'd ask them to experiment with a 15 minute adhoc discussion. Don't use the old standard questions.  In fact don't use any questions.  But get them to agree that they are getting together each day to discuss what they have learned from doing work since the last time they met and how that impacts their plans to accomplish the Sprint Goal. Help them to stay focused by asking "can the two/three/etc of you talk about this more after we finish?".  This honestly has nothing to do with the Daily Scrum. It is a practice for having effective meetings.  

I'm the scrum master of a team, and the developers have organized their meeting to discuss their list of items towards the sprint goal, in a way which the meeting does hit the 30 min mark often. Often times the developers list out a laundry list of tickets/tasks for discussion. If this is the way they have organized their meeting, shall I speak up and try to coach them to limit it to the 15 minutes?

Why are the Developers having these discussions now, in the Daily Scrum? How effectively are they collaborating throughout the rest of the working day? Is this the only time they get together in their role?

I sense that because the Daily Scrum is often 30 minutes (so 15 minutes too long) you want to reduce the time by letting some people not speak.

That's not good!

Everyone should be able to talk. But not too long. If people talk too long the Scrum Master should teach them to talk shorter.

Some people do not talk a lot and they don't mind saying nothinh during the Daily Scrum. However, also during the Daily Scrum they shoud apply the five Scrum values: Courage, Focus, Commitment, Respect, and Openness.