Can you post a sample file explaining where you wanna avoid using aggregation. Aggregation is one of the most useful tools and some calculations simply can't be done without aggregating.
An Eternal "It Depends" - Removing the aggregations may or may not increase performance.
Can try things such as:
Using Set based functions where possible (Depends on what you are doing, sometimes Set performance is better)
Pre-aggregation in the load, possibly through construction of "Summary" or other helper tables (e.g. rather than working off a Fact type table, construct a "summarized by Month(day/week/customer/minute/whatever" type table)
Moving things into individual charts, and minimizing the number displayed at one time (QV is smart enough to not calculate what you can't see)
Again - all calculations are aggregations. It doesn't matter if you write an aggregation function or not, QlikView still needs to aggregate. Read the blog post.
If you want to increase performance, there are several things you can do, but avoiding using an aggregation function does not help. The three bullets in Jim Schepflin's answer are all things that potentially can improve performance.
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