Rules question
 

This has happened twice in Cleveland Browns games this season. In the Baltimore game it was third and three from the 11 yard line, Baltimore had the ball, the runner gained 5 yard to the 6, after the play the runner kicked a Browns player, a flag was thrown and the referee, said "after the play , unsportmanlike conduct agains Baltimore,d penalty and then moved the ball from the 6 yard line to the 21 and said first and ten.

In the Washington game it was third and 8 yards, a pass was completed with enough yardage for a first down. After the catch Pierre Garson was penalized for "taunting" The refereee said, "after the play, a 15 yard penalty against the offense for taunting and marched off 15 yards, now first and ten.

My question in both of these instances is, if a first down had been made, and now a penalty is thrown, why would it not be first and 25 yards instead of marking off a 15 yard penalty and then saying first and 10? Needless to say they lose 15 yards either way, but it is MUCH tougher getting a first down after a first and 25 yards, instead of just moving back 15 yards and then claiming first and ten?

Not sure about the NFL but the other rule codes eliminated 1st and 25 situations several years ago. Only if the foul is committed once the chains are set is a 1-25 scenario possible now.

NFL Rule Book (2012)
Rule 14, Section 8

ADVANCE OF NECESSARY LINE FIRST-AND-10
Article 4 After a distance penalty four a foul by the offensive team during a play from scrimmage which results in the ball being in advance of the necessary line, it is a first-and-10 for the offensive team.

Article 4 and 6 also apply to a dead ball foul of the offensive team at the end of a play from scrimmage during which it has been constantly in possession.

You've kinda answered your own question. 1st-and-25 is basically a turnover, since the chances of making a first down are extremely small.

The rulesmakers felt that the loss of 15 yards in field position was penalty enough.

Under NCAA rules, its once the ready for play has been blown.

Which no longer happens unless there is a stoppage for some reason due to the 40 second play clock

I don't think there would be a 40 second clock after a penalty enforcement, it would be 25 and an RFP.

Incorrect. The referee blows the RFP before every single play.

Especially after a first down when he needs to signal the game clock to restart.

This is not true under NCAA rules. If the clock is set to 40 and runs automatically, there is no RFP blown.

Correct but here he was referring to the foul happening after the RFP. The post was stating there isn't a ready for play whistle or signal after the previous play unless there was an official's time out for something.

So if team A sees the ball on the ground with no official over it, they can go snap it?

No, but that doesn't mean there's a RFP given. The U spots the football and the R directs the U to move away from the ball at the appropriate time (which varies depending on whether A substitutes). Still, there's no RFP blown.

Even then, it's not "technically" a RFP. Ball's spotted, game clock's started, but the 40 second clock is running the entire time. Not what I'd traditionally think of as a RFP.

While I agree, most of those give the "downward chop" RFP, followed immediately by the "wind the clock" signal.