を前提に => On the premise of N1
Premise
じつをいうと => Frankly speaking N2
Story topic
~且つ(かつ) => and N1
Line up, list
つつ => while; even though; despite ~ N2
つつ/つつも => While A, B. Although A (is beng done), B N2
Information, Report
につけ~につけ => each time, whenever, either way N2
べつに => separately N2
Description
~をたて(~を経て)      => through; after; via N1
を => Auxiliary words N5
からつくる/でつくる => made from; made with N4
ひとつ => A little N3
Repetition, habit
いつかの ... => Previously N4
Time