Well i have three diesels at the moment an non of them produce white smoke when there cold, unless the ambient temp is very cold around zero.
How does it start? white smoke can be caused by injection timing being out.
No you wont have a problem that way round, but what will happen eventually is the relay will burn out due to the extra current (amps) being drawn through it, 3 bulbs instead of 2
I assume the relay you fitted is from a disco with 6 indicators?
Are all the indicator bulbs the correct wattage 21w?
When i said six i meant 4 at rear and 2 at front would be 8 including front wing repeaters :)