To clarify: My beef with aesthetics is ONLY the general recommendation I have often seen to research it as "trade bait" before alpha. This might be generally good on Deity and work reasonably well on Pangaea Immortal if one has Mansa and Willem on the map or so but I think it is bad advice below Immortal and doubtful on Immortal as a general recommendation. And of course in isolation one can postpone alpha for a long time.
The Cathy isolation game is discussed here, including some games played until earlyish invasion of neighbors:
http://forums.civfanatics.com/threads/immortal-isolation-desperation.599018/
I am not sure when one has to decide for culture. I am not experienced enough and never got an really early culture win (say before 19th century), probably because I decided too late or it simply took me too long to get all the multiplier buildings. A nontrivial thing in isolation is to get two religions because you need them for the culture multiplier buildings. The three early religions are usually gone too early, so ideally one will be first to both CoL and Philosophy as Caste and pacifism are essential anyway. So it might be good to oracle CoL (unless one has such a strong start that one can directly research it and try to oracle a later tech). For a possible third religion, I tend to hope for some spread after contact but if one gets a priest from the oracle early on, one can bulb Theology.
Then you go on the lib race for the doubled culture of free speech; no delaying lib to get something more expensive (also risky in isolation when one does not know where the others are in tech), nationalism seems an easy choice to liberate for the taj and hermitage.
The pyramids are useful, I think, if one has stone or is IND because they make a specialist economy so much better. Other nice earlyish wonders are the parthenon and maybe the Mausoleum, so marble is really extremely useful, almost necessary, also for Michelangelo's chapel. Without access to marble I'd probably not even consider cultural. I think I got some of these wonders and the two religions without too much trouble on that Cathy map (because stone and marble are there). But I was toast after the whole world could be brought into war (and trade embargo) against me by the AP resident despite being cautious or pleased. Probably more a failure in diplo than in building enough muskets (or whatever) to fall not too far behind in power.
There probably is another culture strategy with cottages and switching all commerce to culture, I tend to prefer specialists (because the culture slider is global but specialists local) but it is probably dependent on traits and map. One should probably not waste a good bureau cap but one will switch to liberalism ASAP anyway for doubling culture and in isolation double seafood+ another food source (or even more in a cap) are not infrequent.
With "late cultural" people probably mean playing first more aggressively and relying on late game multiplier buildings/wonders like broadway. I think that from an isolated start one should be earlier (and early astronomy bulb and medieval or cuirassier invasion would be to the detriment of all those culture techs and builds one needs), so these late wonders will not really matter any more, although one might be late enough to build one of them.
For isolation training there is also the "lonely hearts club" series, having both nice and rather nasty maps (a few are not complete isolation, that is luckily placed cities with some border pops one can get into contact before optics).
