Broadford or Kyle of Lochalsh?

To me, I would say of these two Kyle.

There are far better shopping facilities there, but also you are actually there ready for your train. There would be nothing worse than waiting for 3 hours in Broadford, then the bus not turning up for whatever reason- breakdown, RTA blocking the road, delayed ferry connection from the Outer Hebrides at Uig....

Although the same bus issue would exist there I would suggest a third option- Kyleakin- on the opposite side of the Skye bridge from the Kyle, and the opposite ferryport in the days before the Skye Bridge opened in 1996.
A good cafe there, a very attractive harbour and broad main (only) street.

Superlative views from 'The Lump'- the hillock behind the cafe where the war memorial is.

The name Kyleakin is of Viking origin and translates as “King Haakan’s strait” after the Norse king who was based here before the battle of Largs in 1263.
You can also see under the bridge where Eilean Bàn is, the island between Kyleakin and Kyle of Lochalsh where the author Gavin Maxwell (of Ring of Bright Water fame) once lived, and it's lighthouse.
He lived there for the last year of his life (but had owned the island since 1963) after fire destroyed his cottage at Sandaig (a place known in his books by the name Camusfearna).
You can actually stay in the lightkeepers cottages on the island.

Broadford for me, best fish n chips on the island and the outstanding Coffee Bothy ,go look at thier Instagram.
Theres a set of craft type stalls by the Co-Op too worth a look.

I'd second the idea of getting to Kyle straightaway to avoid any bus connection problems and the potential for missing your train. isn31c's suggestions are excellent and would easily kill the required 3 hours. Also in Kyle there's an excellent cafe cabin on the waterside, where you can get excellent Cullen Skink (a real taste of Scotland).

The Sia fish and chips and the coffee bothy in Broadford are great, but I'd not want to risk missing my train in Kyle.

Jacqui (Skyegirl)