Arthur Conan Doyle lived in South Norwood from 1891 to 1894 i.e. when he wrote the first two volumes. The area is 7.8 miles from the centre of London i.e. Charing Cross and was in Surrey at the time, although it was in the London SE postal district, being SE25 today. The area is a popular one for commuters, with Norwood Junction having no less than six operational platforms for services towards London Bridge; the Overground's East London Line also calls there. ACD does obfuscate some of the locations though.
Blackheath is located 6.4 miles SE from Charing Cross, on what is now the Greenwich/Lewisham boundary.
President Murillo forms a key part of "Wisteria Lodge", which we have already covered.
The Dutch steamship Friesland is also mentioned in The Lost World where it spots an escaped pterodactyl.
The Victorian era saw a massive boom in housebuilding due to a growing population that needed to live near their industrial workplaces - or in close proximity to a railway station so they could commute to their offices. Some of the housing was better than others, with the stuff for the poor being basically slums and mostly cleared away in later decades.
The Anerley Arms, located next to Anerley station (one stop up the line towards London from Norwood Junction), is still an active pub although no longer does hotel accommodation. I've been there quite a few times after events at the nearby Town Hall for an evening meal before heading home. They have a number of Holmes-related pictures on the walls, but don't make the canon connection explicit.
Anerley station itself is two platforms either side of a four-line railway; the original station buildings have been replaced.
It's rather hard to destroy all traces of a body with a wood-based fire set by an amateur. You need a functioning crematorium and England didn't exactly have many of those free for use.
The fire extinguisher as we know it today was around by this time.
