Oh god I'm not even thinking about a day time nap routine! I didn't with DS1 until he was much older, I persevered with getting him into a nap routine in his cot when he was about 6 months and he was then a brilliant napper. He was self settling at night though which probably helped, and it did take some work!
DS2 seems happier to be on his own in his bouncer etc for longer than DS1 was, probably because he's a second child! I'm not in any kind of nap cycle for him, some days he seems to sleep loads, others not much. He's ok ish at sleeping in a Moses etc in the day but I don't know if he'd go down awake in the day time. He does at night sometimes but only if he hasn't fallen asleep on his bottle!
since2016 don't worry about SIDS, the advice to never leave a sleeping baby alone in a room ever is ludicrous and impossible for those of us with two kids. Your DD is EBF, born at term, living in a presumably non smoking household? It's totally fine to leave her with a monitor and pop back at intervals. I do the same.
yakadee no idea sorry, maybe a blister or spot? Weirdly it looks very similar to the mark DS2 had after his lumbar puncture...