Interference?

Probably nothing in this sit.
The BR is allowed, in fact must, leave the running lane to touch 1B.

A running lane violation is generally reserved for plays which the runner gets between F3 and the thrower, usually from HP area.

And is also reserved for quality throws. Though possible, I don't see it for the OP type play.

It's either going to be nothing or obstruction. As mentioned most likely nothing.

When I said he reached into the path of the runner, I mean like in fair territory.
We had several plays like that on the other team, and when their runners correctly touched the base, after coming out of the running lane, we had nothing, no contact, just a close play at first. I think, if we're not gunna call that, it would be wise for the coach to teach his runners to run 'on the grass' then at the last second cut to the base, and maybe disrupt a throw that's right in front of the base.

Up the line, I read as on the line. None the less, the running lane is from and including the foul line to three feet foul. If the contact happens right at the base and the runne has access to some part of the bag then it's nothing unless the BR does something intentional to cause the contact.

Hi Mike, I don't think you're picturing this play as I mean it to. B/R is running on the grass, then at the last second, angles thru the base.

The running lane is only relevant to throws coming from the home plate area - behind the B/R. It is not a factor on a throw from F6.

Could you site a rule.
Everything I read, does not match up with that statement.

It's how the rule is interpreted in all codes. From the 2010 FED Baseball Rules Interpretations: "[The batter/runner] is required to be in the running lane the last 45 feet to first base when the ball is fielded and thrown from an area behind him."