What are the tradeoffs replacing sucrose / table sugar with pure granulater dextrose / glucose?
Table sugar, ie sucrose, is not "a mixture of glucose and fructose", but rather a disaccharide made by combining one molecule of glucose with one of fructose. In the body, the sucrose is metabolised into glucose and fructose; the fructose is further modified into glucose. I'm sure that you don't want to know about the tricarboxylic acid cycle which is how the glucose gets turned into carbon dioxide, water and energy as you are interested in the physical aspects.

Using a larger quantity of glucose (as opposed to sucrose) causes the proportions of all the ingredients to change, causing a change in taste and consistency - in the same way that diabetic foods, using sorbitol, have different consistencies.

Glucose is probably more reactive than sucrose in terms of the Maillard reaction (browning).