Does Weapon Finesse force you into Two Weapon Fighting?

[Darg]

I am working on a build for a tiefling rogue 1/swordsage 4, and I've gone down a rabbit hole from trying to figure out how weapon finesse fits into any melee character's overall build.

If you are playing a point-buy game and you have access to general markets for magic items, taking Weapon Finesse means you are planning to make the commitment to benefit from taking this feat because every class in the game has been described as 'feat-starved'. Therefore

1. you have high dexterity, otherwise you wouldn't benefit from the feat
2. you are plan to use one of the weapons which benefits from the Weapon Finesse feat, otherwise you wouldn't benefit from the feat
3. you have low strength, because a major benefit of Weapon Finesse is that it lets you reduce MADness

Spike chain is the only 2-handed weapon that benefits from that feat (I'm aware of the builds that use it, but for my concerns I'm calling it a unique exception to this problem). Otherwise, taking Weapon Finesse means you need to use at least one weapon that's one-handed. I don't have much experience playing as a melee character in 3.5e, but my limited experiences does match what I see generally posted online which is using a sword and shield is weaker than other melee options, and once you have access to the Animated enchantment it seems hard to justify occupying a hand that you don't need to. It seems like shields just don't provide a high enough AC bonus to justify them, and your high dexterity should get your AC high enough that you can stay in melee combat.

If you take Weapon Finesse, unless you will use a spiked chain do you have to fight with two weapons? Or are there other one-handed or two-handed options I'm missing?

You don't actually have to fight with two weapons. One thing that gets overlooked a lot is that thrown weapons are ranged weapons. Which means they benefit just as much from point blank shot and rapid shot in melee as projectile weapons do. Thus you can get your "extra attack" without TWF.

The druid's flame blade spell or the cleric's ice axe spell make great use of weapon finesse as they don't benefit from the strength bonus to damage. One of my favorite characters was a druid that used TWF flame blades, finesse, and improved critical (scimitar) to great effect.

As you've already figured out, late game you shouldn't be using a shield without the animated property. There's just simply no reason not to. It's the only way in core to get a reliable 3rd hand and really the only way to make the PHBII shield feats worth while.

ToB maneuvers basically negate any real need for TWF as there are many options that are competitive without it.

Hit And Run Tactics (Fighter ACF) (DoTU): It’s frequently misunderstood as a drow-only ACF, but by RAW it isn’t. Give up your heavy armor and tower shield proficiency, and when attacking a flat-footed opponent within 30 feet, add DEX to damage as a competence bonus, i.e. it stacks with other iterations of DEX to damage.

When the advice to DMs is that it's designed for drow characters and the section itself mentions that ACFs are a way to reflect racial choice and character concept, it's as much of a leap as stepping over a crack in the sidewalk.