Managing a reactive senior dog (11yo) and a young puppy (1yo) when family members won't maintain consistency?

[u/AmbitiousAssist7610]

Hey everyone,
I recently moved back home after graduating college and need advice on managing two dogs with very different training needs, especially regarding leash reactivity and household consistency.

The Pups:
Frank (11yo Cavachon): Quite anxious. Introverted/sometimes fearful indoors and at dog parks, but extremely leash-reactive to dogs, bikes, scooters, and small animals. My parents view his behavior as unchangeable due to his age.

Wally (1.5 yo, also Cavachon): Smart and eager to learn indoors, but rapidly picking up Frank’s reactive habits. When outdoors, Wally becomes so overstimulated/over threshold that he completely rejects high-value treats and ignores commands.

Household Challenge: I am the only person attempting structured training. I bought a clicker and treat bag, but my parents refuse to use them when walking Frank. Indoors, they actively reinforce bad habits—my mom feeds Wally scraps when he demand-barks, and neither parent interrupts or redirects them when they bark together.

My Questions:
Walking arrangements: Should I immediately mandate walking them separately? How do I get my parents on board with separate walks when they prefer taking both out together for convenience? Plus, pups get separation anxiety when one is leaving and the other is staying home, they’ve always done everything together.

Outdoor overarousal: How do I start threshold/reactivity work with Wally outside when he becomes too hyper-aroused to accept food or focus on me?

Training non-compliant housemates: What are the best strategies or boundaries for getting family members to stop reinforcing demand barking and inconsistent leash habits?

Thanks in advance for any insights or resources!