What I experienced (on win64):
The metro object seems to only take integer in the second inlet (in msec per tick) When I replicated the patch, the metro object only sent a first bang and stopped working until I put integers values in the second inlet.
Do you see the bang object linked to the metro blinking? If not the 248 clock message will not be sent.
For testing purposes, I opened a renoise instance, configured the slave mode to external clock and did series of click on the 248 message in PD, I saw the clock input led blinking in Renoise.
Since I don’t know your level of knowledge…
In renoise, did you configure Preference > MIDI > MIDI Clock Slave > In device accordingly to receive the output of the clock generated in PD?
Did you attribute a MIDI output device in the PD midi settings?
If yes and yes did you activate the clock button in renoise?
From what I experienced trying to use OSC and lua, the frequency of lua execution is too slow, and I loosed clock ticks, so I would agree with the suggestion of Danoise to use MIDI clock instead of OSC messages for syncing purposes.
For your last question: I just know that I can tell renoise to go on specific pattern number using OSC message from Max, (didnt try in PD):
/renoise/song/sequence/trigger 135
Never searched to activate a pattern from a specific line…
I wish you to get this working!