Looking for advice on structuring my investing portfolio

Hi all,
I’m starting to build out a long-term investment portfolio and would appreciate some outside perspective before I commit more capital.
Current situation:
• €5,000 going into SPPE (S&P 500 UCITS ETF)
• Already hold €700 in IXUA (MSCI World ex-USA), and considering adding another €5,000 there
• Going forward, I can invest €1,000/month, but I’m unsure how to split it going forward
My main questions:
1. Is IXUA (MSCI World ex-USA) a good complement to an S&P 500 core, or would a Europe-only index (e.g. STOXX 600 or similar) make more sense instead? I like the idea of geographic diversification away from the US, but I’m not sure if ex-USA is too broad/unfocused compared to just going Europe-specific.
2. For the monthly €1,000, would you lean toward keeping it simple (just topping up the same two funds proportionally) or splitting it differently as the portfolio grows?
3. Any general critique of this approach for someone investing long-term with a moderate-to-aggressive risk tolerance?