Only what the DM decides. Most such abilities have a listed limit, and IIRC they're usually the same, so maybe steal one of those figures.
It depends.
The rogue's weapon talent doesn't. I have an eladrin rogue in my game who took a feat to use a longsword. He loses a die of sneak attack but can use the sword with two hands (+1 damage) and took the Eladrin Soldier feat (+2 damage to longswords and spears). His [W] and static boosts are higher but he gets fewer sneak attack dice and no dagger talent (I think he might have traded that out for crossbow benefits anyway). It's working out. A typical rogue would have had more accuracy, smaller [W], smaller static boosts and more sneak attack dice. Actually it's not very different in terms of what your PC can do.
Said rogue has a feat that lets him use Fey Step to do Thievery checks at range. It ... almost worked out. He rolled a natural 4, otherwise he could have stolen some keys and been far away before the theft was discovered, and he even arranged for a "cover story". None of this is based on his "build" anyway.
The ranger's combat style is pretty limiting. The specific modifiers are less important than the stats and powers selected. If you're an archer ranger, you pick Dex primary, which means Strength gets neglected and your melee attacks will be weak anyway. Dual-wielding rangers are quite weak (low AC, Wisdom is neglected so your skills are poor). Many ranger powers can be used with both ranged or melee attacks (these usually give you two shots; Twin Strike is the classic one there) so despite your build you can still "switch hit".
I wouldn't say it's much worse than in 3.x.
In any event, a ranger's role is "striker" and both ends match what you're supposed to do.