DF1871: There's no fixed Age the Char's die but i can't remember a char that made it to 60+ because starting with 30 they start to lose Attributepoints, at first the Age-Debuff is minor -1 for STR/END/AGi for reaching 30, -2 STR/AGI and -1 END for reaching 35...but they grow fast and they stack, making the char weaker and weaker despite his experience.

If i remember right there should be a list at the manual, otherwise take a look here
http://darklands.wikia.com/wiki/Agility

DF1871: You can gain basic experience by hunting thieves and robbers in citys during the night, later bandits at the streets, then robberknights...but not all skills/attributes can be raised like this.

Aside from this, you can start with a more experienced party and then recruit new members after you got some equipment/gold and reputation.

Jigby: I remember somebody from the Darklands yahoo group was trying to figure these things out, IIRC, you die of old age at 90.

Note, that the stat degradation happens only in character creation, not in game. Also, the first stat penalty (-1 Str, -1 End) can be nullfied by taking a profession such as Hermit or Knight. Therefore, it makes sense to start with at least 35 years old chars (you take Hermit or Knight at 30 for 5 years, stat penalty negated). From then on, the stat penalties can't be completely negated.

The thing is, Darklands is not that difficult, you can actually push even deeper with professions for more skillpoints, it's a tradeoff between slightly less overall power/better starting equipment and less skill grinding. I like to take Noble Heir at 30 and Knight at 35, that gets you chainmail starting armor - cuts down completely on the initial street thugs cleanup phase.

Also, while aging stat degradation does not occur ingame, it is still possible to lose stat points via ingame events and bugs. If I were you, I'd write down the initial stats of your party, in case of bugs.