#2
Supposedly, it's because band members from Motorhead and Ramones commended each other's work a lot and grew to basically be best friends with each other. Besides, in the earlier times for Lemmy, it was mostly a huge envelopment from Punk and Punk Rock which resulted in him knowing the Ramones and the Ramones went for a heavier tone later on. A vice versa of sorts for each other
#4
No problem. Lemmy inspired a huge amount of musicians throughout the years, and he was inspired by a lot of what the Ramones would later do.