What's wrong with 6-7 ft tonearm wires?

Should be no problem especially if going balanced into the DM10.
Great pre & phono section - I run everything balanced on mine.

Its ok 1 meter is better as its very low level signal.

7 ft may not be a problem but any longer than that if you do A/B comparision you will find decresed resolution.

I experimented 1.2m, 1,5m, 2m, 4m and 6m on my both high out put and low output cartridge ( two diff turntables, diff phonos) using same cable make and found 1.5 m was optimumm with 2m being okay (hair lower resolution) and detrioting significantly as you go longer. At 4m it became pretty obvious.

I should add that all the cables were rca/rca

Nil -- What was the capacitance per foot of the cables?

Best regards,
-- Al