Actually, the opposite is true. Solid wood is more resonant. Higher density = sound travels better. Think about striking a metal tuning fork vs. striking a sponge.
Again, not true. Resonance depends on many factors, but density is generally the biggest one. Tight grained woods, like maple, tend to resonate better on the higher frequencies, while more porous wood resonates more on lower frequencies. Wood that is too soft and porous, or wood that has gaps in it like laminate does, tend to resonate quite poorly. Also, solid wood is not necessarily heavier or thicker than laminate.
The most important thing is how well the instrument is constructed, and the quality of the materials used. The best way to judge is to play it and listen and feel how it responds. There is no hard and fast rule: there may be a laminate top guitar out there that sounds great, and a solid top that sounds like crap. Judge with your ears and hands.
