5 year old multi-stemmed Japanese Tree Lilac leaves get twisted and misshapen every year. It is only slightly larger than when planted and has only flowered the last 2 years and not well. It was planted as a feature specimen but has never performed well and looks scraggly with suckers a frequent problem. Is this normal and if I replace it what would be a great feature small replacement tree or large shrub for full sun on a northeast corner?