I can do the job and I can start right away. I checked the code and I see no problem to work with it. User Friendliness would achieved by focussing on easy and quick parameter loading, security features could include locked cells where no loading required, password protection, data loading coherence check, extensive use of drop downs when input is a selection. If you require further security for code beyond simple password, some extra security can be added to some extent.
About me: I'm an engineer with advanced working knowledge and experience (over 15 years) in Microsoft Excel and VBA including interaction between different software (Word, Excel, Powerpoint, Access, Outlook, MS Project,MS Visio, Autocad, pdf, CorelDraw, PhotoShop, etc.). Also on web scraping, Access DB design, management Dashboards, stock and financial worksheets, KPI's, proficient coder in VB.Net, C#, Python, JavaScript (google sheets), VB6, AI (neural networks, genetic algorithms, optimized search, etc).