Fantastic! Thank you guys....close to a Monstera then, but their labelling could have been somewhat better! I shall try very hard to keep up the good work (although I suspect the plant's success is more down to the plant itself than to anything I'm doing!! - maybe it just likes my windowsill.....) Thanks again - I'm off to read up on it now :-)

Just a common old garden spider.....nothing to worry about and nothing to do with whatever may be ailing your holly (not a Japanese holly, btw). Garden spiders are good things and should be encouraged. FWIW, hollies can be cut back hard and they will backbud or produce new growth from bare stems. Your plants look perfectly healthy otherwise and with no sign of insect or disease issues so why they are so leggy and sparse now is most likely due to cultural conditions....lack of water at some point, possible cold damage at some point or issues with the root ball when planted.

Looks like large pavers. We live in wet winter country - PNW so moss etc is a routine thing here. We use the product Wet and Forget on our smaller pavers which works on moss & grime pretty well. Not all moss is green - it’s black mold looking too. Wet & Forget comes in concentrate or a sprayer container. Needs to be put down when pavers are dry & be able to stay wet for @ hour - so no spraying in sun or heat. Rain comes & washes black away & moss dies so it’s not immediate result but is seen working after the first rain. Not sure how successful this would be in less rainy climate. We buy it at Costco - product is popular here. We did pressure wash our pavers once using a round attachment that gives a much softer wash than the angled hard spray of the angled spray point of pressure washing. We were afraid the pressure washer would lift all the sand filler between the paver joints. ETA: we’ve never sealed our pavers but it is done by some. Need to clean first & I think it’s not permanent so must be redone every few years.

Not sure what issue on the trunk you're asking about, perhaps because the pic is not close enough to tell. Aside, how did it look health-wise last season?