We just scouted Dhal and our map knowledge is now near-perfect, so I don't really want his maps at all.
Is there any way to turn signs off for a prettier overview map?

At Jamestown in the short term I think you're right - the engineer gets us +5 hammers (and an extra 1-turned knight
) while the cottage gets +4 commerce and +2 food for another pop point in ten turns.
Longer term there are two hamlets and a village at present - making 3/4 gpt outside the golden age, Jamestown has no commerce multipliers, but it has *2.25 hammer multiplier. Two watermills get us 2 extra hammers each for 4*2.25=9 hpt and a workshop gets -1 food and +3.5 hammers (I plan to run caste and dip into slavery for short whipping binges for the rest of the game) for 3.5*2.25=7.875 hammers.
The upshot is 10 commerce (rising to 12 in 15 turns and 15 when we get printing press) vs 17 hammers minus one food. Jamestown is only at +2 food now, so the workshop essentially stops growth, but there are no other tiles it needs anyway. I think this is a pretty good trade off, it'll have Jamestown producing 71 hammers per turn for units outside the golden age (rather than the slightly crappy 54 it would otherwise).

Is there any way to turn signs off for a prettier overview map?

At Jamestown in the short term I think you're right - the engineer gets us +5 hammers (and an extra 1-turned knight

Longer term there are two hamlets and a village at present - making 3/4 gpt outside the golden age, Jamestown has no commerce multipliers, but it has *2.25 hammer multiplier. Two watermills get us 2 extra hammers each for 4*2.25=9 hpt and a workshop gets -1 food and +3.5 hammers (I plan to run caste and dip into slavery for short whipping binges for the rest of the game) for 3.5*2.25=7.875 hammers.
The upshot is 10 commerce (rising to 12 in 15 turns and 15 when we get printing press) vs 17 hammers minus one food. Jamestown is only at +2 food now, so the workshop essentially stops growth, but there are no other tiles it needs anyway. I think this is a pretty good trade off, it'll have Jamestown producing 71 hammers per turn for units outside the golden age (rather than the slightly crappy 54 it would otherwise).
Completed: RB Demogame - Gillette, PBEM46, Pitboss 13, Pitboss 18, Pitboss 30, Pitboss 31, Pitboss 38, Pitboss 42, Pitboss 46, Pitboss 52 (Pindicator's game), Pitboss 57
In progress: Rimworld
In progress: Rimworld