Is it just me??? (Proportion)

SL furniture is oversized so that it looks right in the oversized rooms -- which, as has been discussed, are typically at least twice as large as RL rooms. As a result, avatars, even though they're taller than RL people by a ratio of 1.25/1 or so, look tiny on it. Unfortunately, it's impossible to have the furniture look correct both in relation to the room, and in relation to the avatar; most furniture designers choose to size their wares correctly for the architecture, not the people.

BTW, in my starter houses, the ceiling height is very slightly under 5 meters -- 5 minus half the thickness of the floor. That way, I can make a two story house using single 10m prims for the side walls, which saves a few prims in the complete build. You do lose the ability to paint or wallpaper the rooms individually, but I think it's an acceptable tradeoff in a house for First Land.

"You do lose the ability to paint or wallpaper the rooms individually"

Not if you do a 0.125/0.625 cut on the wall prim and line it up so the two halves of the inside face are on each floor, though you can't use hollowed prims for the corners then, or different textures for the outside levels.