The timing chain may need replacement with 275k on it. However if it is not stretched more than ~3 degrees, no you don't HAVE to change it. It's not like a belt you replace every XX thousand miles, you only replace a chain when it's worn (stretched).
As to fluids, some may disagree but I recommend synthetic ATF and engine oil (preferably Mobil products, not Castrol or any "semi-syn" junk.) Definitely do the brake fluid flush every 2 years and use DOT4 fluid (I like Valvoline Syn-Power, it has VERY high ratings and isn't expensive). Finally make sure you don't have the Green Death in the cooling system, if so, flush it out and put in genuine Mercedes anti-freeze - it really is different than anything else on teh market, and at ~$11/gallon it's not an outrageous expense every 2-3 years.
For brake bleeding/flushing, a pressure bleeder is the only way to go (those who claim otherwise have usually never used a pressure bleeder!)
You can build your own (search Google) or get this nifty kit for $39:
http://www.falcotools.com/html/euro_kit.html
Regards,